A fan includes a motor, an impeller and a heat-dissipating structure. The motor includes a stator magnet assembly, a frame, a first circuit board, and a cover. The frame supports the stator magnet assembly. The frame and the stator magnet assembly define a first accommodating space, and the first circuit board is disposed in the first accommodating space. The cover covers the first circuit board. The motor drives the impeller and the impeller includes a hub and a plurality of first blades. The hub has at least a heat-dissipating hole. The first blades are disposed around the hub, and the heat-dissipating structure is disposed at the outer side of the hub. The heat-dissipating structure has a baffle and at least a second blade extended from the baffle and located corresponding to the heat-dissipating hole.