A muscle electrostimulation device (10) includes: a main body (20) having a contact surface (10b) fitted around a portion fitted with the device (10) of a lower limb (6) or an upper limb. The contact surface (10b) extends in an X direction encircling the portion fitted with the device (10) and in a Y direction perpendicular to the X direction. The main body (20) is provided with a pair of electrodes (32) arranged at a distance in the Y direction. Each of the pair of electrodes (32) is shaped in a band in which an extent in the X direction is larger than an extent in the Y direction and is arranged to cause an electric current to flow in the portion fitted with the device (10) along a direction of extension of a muscle fiber in the portion fitted with the device (10).