A vehicle height adjusting device includes: a changing unit that changes relative positions of a vehicle main body and wheels of a vehicle; and a control unit that adjusts a vehicle height that is a height of the vehicle main body by controlling the changing unit to change the relative positions, in which the changing unit includes an electromagnetic valve that is provided on a circulation path of a fluid and that is adjusted to have an opening amount in accordance with supplied power and changes the relative positions as pressure of the fluid varies in accordance with the opening amount of the electromagnetic valve, and the control unit performs Pulse-Width-Modulation control on voltage applied to the electromagnetic valve so that the opening amount of the electromagnetic valve equals a desired opening amount.