Congress sets the salary of the members of the Board of Governors. In 2008, the chairman (Ben Bernanke) makes $191,300 and other board members make $172,200.
His and other board members salaries are expenses of the Federal Reserve Board. The Board gets revenue mainly from levying assessments on the Federal Reserve district banks. The Federal Reserve district banks get most of their revenue from interest on U.S. Government securities. Excess earnings beyond expenses are returned to the U.S. Treasury.