A fan device includes two magnetic members, a fan and a wire. The fan is disposed between the magnetic members, and includes a rotatable hub and a plurality of fan blades radiating from the hub. The wire is mounted on the fan, and has two electrode ends and a plurality of induction portions that are disposed between the electrode ends. Each induction portion is coupled to a respective fan blade, and is co-rotatable with the respective fan blade to intersect a magnetic field between the magnetic members to thereby generate an induced current that flows toward the electrode ends of the wire.