Exhibit 5.1


                       [Letterhead of ASML Holding N.V.]




May 28, 2003


United States Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C.  20549




Ladies and Gentlemen:

         I refer to the Registration Statement on Form S-8 (the "Registration
Statement") of ASML Holding N.V., a Netherlands corporation (the "Company"),
filed on or about May 28, 2003 with the Securities and Exchange Commission
(the "Commission") under the Securities Act of 1933 (the "Securities Act").
The Registration Statement relates to up to 6,723,359 ordinary shares of ASML
Holding N.V. (the "Ordinary Shares"), issuable under the ASML New Hires and
Incentive Stock Option Plan (Version 2002), the ASML Stock Option for
Performance Appraisal Plan (Version 2002) and the ASML Stock Option Plan
(Version 2003) (the "Plans").

         I have examined and am familiar with (i) the Company's Articles of
Association, as amended and (ii) the corporate proceedings relating to the
Registration Statement. Upon the basis of the foregoing, and having satisfied
myself as to such other matters of law and fact as I consider relevant for the
purposes of this opinion, I advise you that, in my opinion, upon issuance in
accordance with the terms and conditions of the Plans, the Ordinary Shares
will have been legally issued, fully paid and non-assessable.

         I express no opinion herein, on or with respect to, any law other
than the laws of The Netherlands and I express no opinion on, or with respect
to, the laws of the United States, any state thereof or any other laws,
statutes, regulations or ordinances.

         I hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and any reference to me therein. In giving such
consent, I do not hereby admit that I am in the category of persons whose
consent is required under Section 7 of the Securities Act or the rules and
regulations of the Commission.

                                            Very truly yours,

                                            /s/ Robert F. Roelofs
                                            ------------------------------------
                                            Robert F. Roelofs
                                            General Counsel