Exhibit 31.2CERTIFICATION OF CHIEF FINANCIAL OFFICERI, Craig A. McCollam, certify that:1. I have reviewed this Quarterly Report on Form 10-Q of Dionex Corporation; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact oromit to state a material factnecessary to make the statements made, in light of the circumstances under which suchstatements were made, not misleading withrespect to the period covered by this report; 3. Based on my knowledge, the financial statements, and other financial information included inthis report, fairly present in allmaterial respects the financial condition, results of operations and cash flows of theregistrant as of, and for, the periods presentedin this report; 4. The registrant’s other certifying officer(s) and I are responsible for establishing andmaintaining disclosure controls and procedures(as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financialreporting (as defined in ExchangeAct Rules 13a-15(f) and 15d-15(f)) for the registrant and have: (a) Designed such disclosure controls and procedures, or caused such disclosurecontrols and procedures to be designed under our supervision, to ensure that materialinformation relating to the registrant, including its consolidated subsidiaries, is madeknown to us by others within those entities, particularly during the period in which thisreport is being prepared;  (b) Designed such internal control over financial reporting, or caused such internalcontrol over financial reporting to be designed under our Company supervision, to providereasonable assurance regarding the reliability of financial reporting and the preparationof financial statements for external purposes in accordance with generally acceptedaccounting principles;  (c) Evaluated the effectiveness of the registrant’s disclosure controls and proceduresand presented in this report. Our conclusions about the effectiveness of the disclosurecontrols and procedures, as of the end of the period covered by this report based on suchevaluation; and  (d) Disclosed in this report any change in the registrant’s internal control overfinancial reporting that occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that has materiallyaffected, or is reasonably likely to materially effect, the registrant’s internal controlover financial reporting; and5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recentevaluation of internal control overfinancial reporting, to the registrant’s auditors and the audit committee of the registrant’sboard of directors (or persons performingthe equivalent functions): (a) All significant deficiencies and material weaknesses in the design or operation ofinternal control over financial reportingwhich are reasonably likely to adversely affect the registrant’s ability to record,process, summarize and report financialinformation; and  (b) Any fraud, whether or not material, that involves management or other employees who have asignificant role in theregistrant’s internal control over financial reporting.   Date: November 9, 2006     /s/ Craig A. McCollam  Craig A. McCollam  Vice President and Chief Financial Officer