Patent ID: 8602804

Claim:
A power plug locking device that prevents unauthorized removal of a power plug from an inlet, wherein the power plug includes an operation arm that is able to be hooked to the inlet, the power plug locking device comprising: a lock unit that restricts movement of the operation arm when the operation arm is hooked to the inlet, wherein the lock unit includes: a first member moved between a lock position and an unlock position; and a second member of which movement is restricted in accordance with the movement of the first member, wherein the second member restricts the movement of the operation arm in cooperation with the first member that is moved to the lock position, wherein: the first member includes a first contact surface; the second member includes a second contact surface that is able to contact the first contact surface of the first member that is moved to the lock position; and at least one of the first contact surface and the second contact surface is formed with a stepped shape.