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EXHIBIT 31.1

CERTIFICATION

I, Lukas Braunschweiler, certify that:



|1. |  | I have reviewed this quarterly report on Form 10-Q of Dionex
Corporation;
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|2. |  | Based on my knowledge, this quarterly 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;
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|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 registrant as of, and for, the periods presented in
this report;
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|4. |  | The registrants other certifying officer(s) and I are responsible
for establishing and maintaining disclosure controls and procedures (as
defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
registrant and we have:
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| | (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
registrant, 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;
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| | (b) |  | evaluated the effectiveness of the registrant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
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| | (c) |  | disclosed in this report any change in the registrants
internal control over financial reporting that occurred
during the registrants most recent fiscal quarter (the
registrants fourth fiscal quarter in the case of an annual report)
that has materially affected, or is reasonably likely to materially
affect, the registrants internal control over financial reporting;
and
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|5. |  | The registrants other certifying officers and I have disclosed,
based on our most recent evaluation of internal control over financial
reporting, to the registrants auditors and the audit committee of the
registrants Board of Directors (or persons performing the equivalent
functions):
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| | (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 registrants
ability to record, process, summarize and report financial
information; and
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| | (b) |  | any fraud, whether or not material, that involves
management or other employees who have a significant role in the
registrants internal control over financial reporting.
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Date:/s/ Lukas Braunschweiler

Lukas BraunschweilerPresident, Chief Executive Officer and Director