Nicor Gas Company
                                                                       Form 10-K
                                                                   Exhibit 24.01


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ ROBERT M. BEAVERS, JR.
-------------------------------
Robert M. Beavers, Jr.


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ BRUCE P. BICKNER
---------------------
Bruce P. Bickner


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ JOHN H. BIRDSALL, III
-------------------------------
John H. Birdsall, III


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ THOMAS A. DONAHOE
-------------------------------
Thomas A. Donahoe


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ THOMAS L. FISHER
--------------------------
Thomas L. Fisher


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ JOHN E. JONES
-------------------------------
John E. Jones


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ DENNIS J. KELLER
--------------------------
Dennis J. Keller


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ WILLIAM A. OSBORN
-------------------------------
William A. Osborn


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ JOHN RAU
--------------
John Rau


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ JOHN F. RIORDAN
-------------------------------
John F. Riordan


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ RUSS M. STROBEL
--------------------------
Russ M. Strobel


<PAGE>


                                POWER OF ATTORNEY


The undersigned, a Director, Officer, or Director and Officer of Nicor Inc. and
Northern Illinois Gas Company (doing business as Nicor Gas Company), Illinois
corporations, hereby authorizes any officer of Nicor Inc. and each of them, to
execute in the name and on behalf of the undersigned as such Director, Officer,
or Director and Officer, the 2003 Annual Report on Form 10-K of Nicor Inc. and
Nicor Gas Company (and any amendments thereto) to be filed pursuant to the
Securities Exchange Act of 1934.



Date:  January 15, 2004





/s/ PATRICIA A. WIER
--------------------------
Patricia A. Wier