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Exhibit 12.1

CERTIFICATION

I, Gabi
Seligsohn, certify that:

1.       
          I have reviewed this annual report on Form 20-F of Nova Measuring Instruments
          Ltd.

2.       
          Based on my knowledge, this report does not contain any untrue statement of a
          material fact or omit to state a material fact necessary to make the statements
          made, in light of the circumstances under which such statements were made, not
          misleading with respect to the period covered by this report;

3.       
          Based on my knowledge, the financial statements, and other financial information
          included in this report, fairly present in all material respects the financial
          condition, results of operations and cash flows of the company as of, and for,
          the periods presented in this report;

4.       
          The companys other certifying officer and I are responsible for
          establishing and maintaining disclosure controls and procedures (as defined in
          Exchange Act Rules 13a-15(e) and 15d-115(e)) and internal control over financial
          reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the
          company and have:

| | (a)       
Designed
such disclosure controls and procedures, or caused such disclosure           controls and
procedures to be designed under our supervision, to ensure that           material
information relating to the company, including its consolidated           subsidiaries,
is made known to us by others within those entities, particularly           during the
period in which this report is being prepared;
| | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (b)       
Designed
such internal control over financial reporting, or caused such           internal control
over financial reporting to be designed under our supervision,           to provide
reasonable assurance regarding the reliability of financial reporting           and the
preparation of financial statements for external purposes in accordance           with
generally accepted accounting principles;
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (c)       
Evaluated
the effectiveness of the companys disclosure controls and           procedures and
presented in this report our conclusions about the effectiveness           of the
disclosure controls and procedures, as of the end of the period covered           by this
report based on such evaluation; and
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (d)       
Disclosed
in this report any change in the companys internal control over           financial
reporting that occurred during the period covered by the annual report           that has
materially affected, or is reasonably likely to materially affect, the           companys
internal control over financial reporting; and
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

5.       
          The companys other certifying officer and I have disclosed, based on our
          most recent evaluation of internal control over financial reporting, to the
          companys auditors and the audit committee of companys board of
          directors (or persons performing the equivalent function):

| | (a)       
All
significant deficiencies and material weaknesses in the design or operation           of
internal control over financial reporting which are reasonably likely to
          adversely affect the companys ability to record, process, summarize and
          report financial information; and
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (b)       
       Any
fraud, whether or not material, that involves management or other employees           who
have a significant role in the companys internal control over           financial
reporting.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Date: March 28, 2008

/s/ Gabi SeligsohnGabi Seligsohn, President and
Chief Executive Officer



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