**Exhibit 31.1**     I, Arthur Zafiropoulo, certify that:     1. I have reviewed this annual report on Form 10-K/A of Ultratech, Inc.;     2. Based on my knowledge, this report does not contain any untrue statement of a materialfact or omit to state a material fact necessary to make the statements made, in light of thecircumstances under which such statements were made, not misleading with respect to the periodcovered by this report;     3. Based on my knowledge, the financial statements, and other financial informationincluded in this report, fairly present in all material respects the financial condition, resultsof operations and cash flows of the registrant as of, and for, the periods presented in thisreport;     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) and15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules13a-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 made knownto us by others within those entities, particularly during the period in which this report isbeing prepared;     b) Designed such internal control over financial reporting, or caused suchinternal control over financial reporting to be designed under our supervision, to providereasonable assurance regarding the reliability of financial reporting and the preparation offinancial statements for external purposes in accordance with generally accepted accountingprinciples;     c) Evaluated the effectiveness of the registrant’s disclosure controls andprocedures and presented in this report our conclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period covered by this report based onsuch evaluation; 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 affect, the registrant’s internal control overfinancial reporting; and     5. The registrant’s other certifying officer(s) and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to the registrant’s auditors andthe audit committee of registrant’s board of directors (or persons performing the equivalentfunctions):     a) All significant deficiencies and material weaknesses in the design oroperation of internal control over financial reporting which are reasonably likely to adverselyaffect the registrant’s ability to record, process, summarize and report financial information;and     b) Any fraud, whether or not material, that involves management or other employeeswho have a significant role in the registrant’s internal control over financial reporting.        Date:  April 30, 2007 /S/ ARTHUR ZAFIROPOULO   Arthur Zafiropoulo   *Chief Executive Officer*