A recirculation fan includes a casing, a covering member, a wind-guiding device, a passive impeller, and an active impeller. The covering member is coupled with the casing to define an accommodation space. The wind-guiding device is disposed on the covering member, and includes a wind-guiding cover and a magnetoresistive structure. The magnetoresistive structure is disposed on the covering member and the wind-guiding cover. The passive impeller is disposed within the accommodation space. The active impeller is disposed within the accommodation space and located beside the passive impeller for generating a wind to drive rotation of the passive impeller and the wind-guiding cover. In response to a magnetic torque resulted from a magnetic vortex of the magnetoresistive structure, a rotating speed of the wind-guiding cover is slowed down.