POWER OF ATTORNEY

      Know all by these presents, that the undersigned
hereby constitutes and appoints each of , Jane Shaw,
Robert Breuil and Nancy Isaac signing individually, the
undersigned?s true and lawful attorneys-in fact and agents
to:

   (1)	execute for and on behalf of the
undersigned, an officer, director or holder of 10% of
more of a registered class of securities of Aerogen,
Inc. (the ?Company?), Forms 3, 4 and 5 in
accordance with Section 16(a) of the Securities
Exchange Act of 1934, as amended (the ?Exchange
Act?) and the rules thereunder;

   (2)	do and perform any and all acts for and on
behalf of the undersigned that may be necessary or
desirable to complete and execute such Form 3, 4 or
5, complete and execute any amendment or
amendments thereto, and timely file such forms or
amendments with the United States Securities and
Exchange Commission and any stock exchange or
similar authority; and

   (3)	take any other action of any nature
whatsoever in connection with the foregoing which,
in the opinion of such attorney-in-fact, may be of
benefit, in the best interest of, or legally required
by, the undersigned, it being understood that the
documents executed by such attorney-in fact on
behalf of the undersigned pursuant to this Power of
Attorney shall be in such form and shall contain
such terms and conditions as such attorney-in-fact
may approve in such attorney-in-fact?s discretion.

      The undersigned hereby grants to each such
attorney-in-fact full power and authority to do and perform
any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the
rights and powers herein granted, as fully to all intents and
purposes as the undersigned might or could do if personally
present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-
fact, or such attorney-in-fact?s substitute or substitutes,
shall lawfully do or cause to be done by virtue of this
power of attorney and the rights and powers herein granted.
The undersigned acknowledges that the foregoing
attorneys-in-fact, in serving in such capacity at the request
of the undersigned, are not assuming, nor is the Company
assuming, any of the undersigned?s responsibilities to
comply with Section 16 of the Exchange Act.

      This Power of Attorney shall remain in full force
and effect until the earliest to occur of (a) the undersigned
is no longer required to file form 3, 4 and 5 with respect to
the undersigned?s holdings of an transactions in securities
issued by the Company, (b) revocation by the undersigned
in a signed writing delivered to the foregoing attorneys-in-
fact or (c) as to any attorney-in-fact individually, until such
attorney-in-fact shall no longer be employed by the
Company.

      IN WITNESS WHEREOF, the undersigned has
cause this Power of Attorney to be executed as of this 22nd
day of April, 2005.


      /s/ Richard Daly

