A massage device includes an outer housing, an inner housing, a drive motor, a gear assembly, a one-way bearing, a drive gear wheel, at least one massage member, and a linear motion device. The massage member can perform a massage through rotary motion and linear motion, and can massage by repeatedly moving forwards and backwards with respect to the user or at fixed positions. Furthermore, the gear wheels of the gear assembly are vertically disposed in the inner housing, while the drive motor is arranged in an oblique manner. Therefore, the inner housing doesn't need a large space to accommodate the gear assembly, and, consequently, the outer housing is also reduced in width.