A limited slip differential device has differential gears (3, 4, 5), a clutch (7) to limit the differential function of the differential gears (3, 4, 5), and a electromagnetic solenoid (8) including a plunger (83) and a coil (82). The plunger (83) is set to move forward to engage the clutch (7) by electromagnetic force of the coil (82) in a differential limit state and move backward by a return spring (12) to disengage the clutch (7) in a differential limitless state. The plunger (83) contacts with a contacting member (81) in at least one state of the differential limit state and the differential limitless state, and their contact area is set smaller than a facing area (BB) between them in at least the one state.