An electric fan includes a fan base (10), a bearing (40) and a rotor assembly (20). The fan base forms a central tube (11) receiving the bearing therein. The rotor assembly includes a fan hub (22), and a pivot axle (23) joined to the fan hub. The pivot axle pivotably extends into the bearing. A sealing lid (60) is screwedly mounted on a bottom opening of the central tube to prevent lubricant oil contained in the central tube from leaking. The sealing lid abuts against a bottom of the bearing to prevent the bearing from deflection.