To provide a suspension device which satisfies both stroke length and mountability on a vehicle.

The suspension device S includes: a motion conversion mechanism T which includes a linearly moving member 1 and a rotating member 2 and converts linear motion of the linearly moving member 1 to rotational motion of the rotating member 2; a motor M including a rotor 3 connected to the rotating member 2; and a fluid pressure damper D connected to the linearly moving member 1. In the suspension device S, a rotary damper is used as the fluid pressure damper D, and the fluid pressure damper D is set in such a manner that when the damper rotor 11 is rotated relative to a housing 10, attenuation force for suppressing rotation of the damper rotor 11 relative to the housing 10 is exhibited, and the damper rotor 11 is connected to the linearly moving member 1 so as to be rotated by linear motion of the linear member 1.