An apparatus for fixing a fan on a specific surface is disclosed, which comprises: a bracket, formed with a hollow section; a plurality of side panels, disposed on the specific surface as an array while enabling each side panel to be disposed perpendicular to the specific surface and the bracket; a first clamping piece; and a second clamping piece. The fan is sandwiched between any two neighboring side panels while enabling an end of the fan module where the first clamping piece is mounted to face toward the hollow section. The first clamping piece is configured with a spring that is capable of moving relatively to the fan so as to enable a first protrusion formed on the spring to inset into the hollow section when the spring is moved to a first position, and detach from the hollow section when the spring is move to a second position.