**Exhibit 12.2**

**Section 302Certification**

I, Wolfgang Bremecertify that:

1. I have reviewed thisannual report on Form 20-F for the fiscal year ended December 31,2005 of AIXTRON Aktiengesellschaft (the “Company”);

2. Based on myknowledge, this report does not contain any untrue statement of a material factor omit to state a material fact necessary to make the statements made, inlight of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

3. Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the Company as of, and for,the periods presented in this report;

4. The Company’s othercertifying 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)) for the Company and have:

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

(b) Evaluated theeffectiveness of the Company’s disclosure controls and procedures and presentedin this report our conclusions about the effectiveness of the disclosurecontrols and procedures, as of the end of the period covered by this reportbased on such evaluation; and

(c) Disclosed inthis report any change in the Company’s internal control over financialreporting that occurred during the period covered by the annual report that hasmaterially affected, or is reasonably likely to materially affect, the Company’sinternal control over financial reporting; and

5. The Company’s othercertifying officer(s) and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the Company’sauditors and the audit committee of the Company’s board of directors (orpersons performing the equivalent functions):

(a) All significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting which are reasonably likely to adverselyaffect the Company’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 the Company’s internal control over financial reporting.

Date:  June 22,2006
|                                            |       |                                                       |
|--------------------------------------------|------------|------------------------------------------------------------|
| /s/    WOLFGANG  BREME |
| Name:                                      | ** ** | **Wolfgang  Breme**                                        |
| Title:                                     | ** ** | **Executive  Vice President and Chief Financial  Officer** |
|                                            |            |                                                            |  |  |

 

 

----