A sheet process device includes a processing part unit and a leg part unit. The processing part unit performs post process for a sheet ejected from an image forming apparatus. The leg part unit supports the processing part unit height-adjustably. The leg part unit includes a leg member, a fixed supporting member, and a movable supporting member. The leg member is extendable/contractable in upward and downward directions. The fixed supporting member is extended from a lower end of the leg member in a horizontal direction. The movable supporting member is stored in the fixed supporting member at the lower end of the leg member and extended in another horizontal direction being different from the extending direction of the fixed supporting member.