TERADYNE, INC. SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN

(a)

Accrued Benefit has the same meaning as such term has in the Retirement Plan after December 31, 2004, but calculated under the terms of the Plan. If Retirement Benefits commence prior to Social Security Retirement Age, the factors in Appendix A, Column B of the Retirement Plan will be used for this calculation.

(b)

Actuarial Equivalent has the same meaning as such term has in the Retirement Plan.

(c)

Affiliate shall mean—

(1)

any corporation other than the Company which together with the Company is a member of a “controlled group” of corporations (as defined in Code Section 414(b));

(2)

any organization which together with the Company is under “common control” (as defined in Code Section 414(c));

(3)

any organization which together with the Company is an “affiliated service group” (as defined in Code Section 414(m)); or

(4)

any other entity required to be aggregated with the Company pursuant to regulations under Code Section 414(o).

(d)

Annual Compensation has the same meaning such term has under the Retirement Plan without the limitations of Section 401(a)(17) of the Code.

(e)

Beneficiary shall mean the person or persons last designated by a Member, in such manner as the Plan Administrator deems appropriate, to receive any benefits for which a Beneficiary is eligible under this Plan, or if there is no living Beneficiary the Member’s Spouse, and if no living Spouse, then the Member’s estate.

(f)

Code shall mean the Internal Revenue Code of 1986, as the same shall from time to time be amended, and the guidance issued thereunder.

(g)

Committee shall mean any Committee of the Board of Directors of the Company designated by the Board to have any responsibility with respect to the Plan.

(h)

Company shall mean Teradyne, Inc.

(i)

Compensation :

(1)

for those Members who became Members under the Plan before January 1, 2003, shall mean for each Plan Year,

(A)

an amount equal to the Annual Compensation minus

(B)

actual payments to the Member under the Variable Compensation Plan for such Plan Year, plus

(C)

target variable portions of the Member’s Model Compensation for the Plan Year as of the most recent effective date as of when the Model Compensation is fixed for the Member.

(2)

for Members who became Members after January 1, 2003 (or hereafter become Members), shall mean for each Plan Year, an amount equal to Annual Compensation, but only to the extent it exceeds the limit under Section 401(a)(17) of the Code during such Plan Year.

(j)

Covered Compensation shall mean the Breakpoint for each Plan Year after 1988 as defined in Section 2.1(g)(3) of the Retirement Plan.

(k)

Credited Service has the same meaning as such term has in the Retirement Plan.

(l)

Disability has the same meaning as such term has in the Retirement Plan.

(m)

Earliest Retirement Date has the same meaning as such term has in the Retirement Plan as of January 1, 2005.

(n)

Eligible Employee shall mean an Employee who is an “Eligible Employee” as defined in the Retirement Plan (and who had elected to continue to accrue benefits under the Retirement Plan after October 29, 1999), and who was a Member of the Prior Plan on December 31, 2004, or, thereafter is eligible for Model Compensation in excess of the Section 401(a)(17) limit in any Plan Year in which he is employed by Employer, and has been notified that he or she is an Eligible Employee under this Plan by the Plan Administrator. No Employee shall be considered an Eligible Employee after October 29, 1999 if such Employee experiences a Break in Service under the Retirement Plan and any Retirement Benefits shall be based on the terms of this Plan (and the Prior Plan) prior to such Break in Service and such Member’s service and compensation at that time.

(o)

Employee shall mean an individual who is employed by the Employer as a regular employee or an expatriate employee on the U.S. payroll and who is regularly scheduled for 20 or more hours of service per week taking into account Hours of Service as defined in the Retirement Plan.

(p)

Employer shall mean the Company and any Affiliate that has been included in the Prior Plan (or is hereafter included in this Plan) with respect to some or all of its Eligible Employees.

(q)

Final Average Compensation shall mean the sum of the Employee’s Monthly Compensation for the 5 Plan Years during which the Employee’s aggregate Monthly Compensation was the highest, divided by five; provided, however, that if the Employee terminated employment on any day other than the last business day of the Plan Year, then, if higher, Final Average Compensation shall mean the sum of the Member’s Monthly Compensation during the 60 consecutive months ending with the month prior to the Member’s termination date, if higher; and provided further that if the Employee has fewer than sixty consecutive months of employment with the Employer or his or her termination date, Final Average Compensation shall mean the Employee’s average Monthly Compensation during the period of his or her employment with the Employer.

(r)

Grandfathered Benefits shall mean the accrued and vested benefits under the terms of the Prior Plan as of December 31, 2004 as defined for purposes of Section 409A and subject to the terms of the Prior Plan as in effect on October 3, 2004 and as amended thereafter consistent with Section 409A.

(s)

Member shall mean an Employee who has satisfied the requirements of Article III.

(t)

Model Compensation is Employee’s base salary plus target variable payout under the terms of the Variable Compensation Plan.

(u)

Monthly Compensation shall mean Compensation divided by 12 except that, for the year in which a Member terminates employment, Compensation shall be determined with respect to the period of service completed in such year, divided by the number of such months (including any partial months).

(v)

Normal Retirement Date is the date the Member reaches Social Security Retirement Age.

(w)

Plan Administrator shall mean the Retirement Plan Committee, as described in the Retirement Plan, or any other person designated as Plan Administrator by the Board of Directors or a Committee.

(x)

Plan Year shall mean the calendar year.

(y)

Retirement Benefits shall mean the benefits provided under Section 4.1 of this Plan.

(z)

Retirement Plan shall mean the Retirement Plan for Employees of Teradyne, Inc., as amended from time to time.

(aa)

Separation from Service shall mean a Member’s termination of employment with an Employer within the meaning of Section 409A.

(bb)

Social Security Retirement Age has the same meaning as such term has under the Retirement Plan as of January 1, 2005.

(cc)

Spouse , Surviving Spouse and the term “ married ” shall be interpreted under the law of the jurisdiction in which the Member was married.

(dd)

Variable Compensation Plan shall mean the Teradyne, Inc. Variable Compensation Plan as modified and incorporated into the Teradyne, Inc. 2006 Equity and Cash Compensation Incentive Plan, each as amended from time to time.

(a)

Entitlement to Retirement Benefits . Except as provided in Section 4.7, a Member who Separates from Service after December 31, 2004 and who is vested under the terms of Article V is entitled to the receipt of Retirement Benefits determined in Section 4.2, payable in the manner provided in the Member’s election under Section 4.4 of Plan with respect to all amounts accrued or vested after December 31, 2004.

(b)

Amount of Retirement Benefits . A Member who,

I.

first became a Member prior to January 1, 2003, shall be entitled to a monthly Retirement Benefit equal to one-twelfth of the result of (1) minus (2) minus (3) where—

(1)

is an amount payable in a straight life annuity form equal to the product of (i) the Member’s Credited Service and (ii) the sum of (A) and (B) as follows:

(A)

0.75 percent of the Member’s Final Average Compensation up to the Covered Compensation,

(B)

1.50 percent of the Member’s Final Average Compensation above the Covered Compensation,

(2)

is the Member’s Accrued Benefit payable in a straight life annuity form from the Retirement Plan; and

(3)

is the Member’s Accrued Benefit payable in a straight life annuity form under the Prior Plan with respect to amounts accrued and vested within the meaning of Section 409A prior to January 1, 2005; or

II.

first became a Member on or after January 1, 2003, shall be entitled to a monthly Retirement Benefit equal to one-twelfth of (1) minus (2) when