An impeller of an advection-type fan includes a metal base plate, a shaft and a plurality of plastic blades. The metal base plate includes a shaft-coupling portion and a peripheral portion, with a first plane facing in a first direction and a second plane facing in a second direction opposite to the first direction arranged between the shaft-coupling portion and the peripheral portion. The metal base plate is in a plane form between the shaft-coupling portion and the peripheral portion. The shaft has a fixing end and a free end. The fixing end is coupled with the shaft-coupling portion, and the free end extends in the first direction. Each plastic blade has a coupling portion and an air-driving portion. The coupling portion is coupled with the peripheral portion, and the air-driving portion extends in the second direction.