An electric motor is provided with an annular member supported by a cylindrical member of a front housing. The annular member includes an opposite part spaced from a surface of a ring member in a rotary shaft, which extends in the circumferential direction. The annular member includes first cover part opposed to first surface of the ring member, and second cover part opposed to second surface of the ring member. The first cover part and the second cover part are spaced from the ring member so that a pressure in a space sandwiched by the first cover part and the first surface is equalized with a pressure in a space sandwiched by the second cover part and the second surface.