Disclosed is a device for promoting decomposition of body fat and enhancing muscular strength, comprising: a base seated on a horizontal surface; a post uprightly provided in the front part of the base; a foothold mounted to be vertically movable on the base; a drive unit provided in the base to periodically and alternately raise and lower the opposite ends of the foothold; and a control section provided on the post for controlling the drive of the drive unit. The drive unit comprises a drive source mounted on the base, rotational shafts, which are respectively connected to driving axes extending from the opposite sides of the drive source, balance weights each being secured to one of the rotational shafts, which extend through the balance weights, eccentric axles each being directly formed on one of the rotational shafts, and connecting rods each being connected to one of the eccentric axles.