An electric steering lock device which can prevent a motor from being overloaded and can increase the drive force of the motor. The electric steering lock device (10) of the present invention has a lock bar (22) that moves according to the movement of a lift member (50). In a state where female threads (52) provided on the lift member are threadably engaged with male threads (45) provided on a rotary shaft (40), the lift member moves along the axis of the rotary shaft according to the rotation of the rotary shaft, which is driven by an electric motor (11). The female threads of the lift member can be disengaged from the male threads according to the rotation of the rotary shaft. When the female threads are disengaged from the male threads, rotation of the rotary shaft (40) is permitted.