A steering lock device which performs a steering lock in such a way that a lock bar is advanced into a projected state and is thus locked to a steering of a vehicle, and releases the steering lock in such a way that the lock bar is retreated into a retracted state and the locking of the lock bar to the steering is thus released, the steering lock device comprising: a case member; a lock bar attached to the case member; a motor having an output shaft which is arbitrarily rotatable in a normal direction and in a reverse direction; a driving gear member which is attached to the output shaft of the motor and which is rotatable together with the output shaft; a driven gear member which is assembled in a state of being meshed with the driving gear member, which is rotatable in a direction corresponding to a rotation direction of the driving gear member and which has a female thread; and a feed screw member which is connected coaxially with the lock bar, which has a male thread screwed with the female thread of the driven gear member and which is capable of causing the lock bar to advance or retreat in an axial direction by the rotation of the driven gear member, wherein the motor, the feed screw member and the lock bar are accommodated in parallel within the case member, characterized by an overload protection module configured to block the transmission of a driving force of the motor to the lock bar when an overload occurs in the course of the lock bar being advanced, wherein the driven gear member comprises a first driven gear member having a gear which is meshed with the driving gear member and a second driven gear member having the female thread, and the overload protection module comprises a torque limiter which is interposed between the first driven gear member and the second driven gear member, and wherein when an overload occurs in the lock bar, the first driven gear member is idled with respect to the second driven gear member. a case member; a lock bar attached to the case member; a motor having an output shaft which is arbitrarily rotatable in a normal direction and in a reverse direction; a driving gear member which is attached to the output shaft of the motor and which is rotatable together with the output shaft; a driven gear member which is assembled in a state of being meshed with the driving gear member, which is rotatable in a direction corresponding to a rotation direction of the driving gear member and which has a female thread; and a feed screw member which is connected coaxially with the lock bar, which has a male thread screwed with the female thread of the driven gear member and which is capable of causing the lock bar to advance or retreat in an axial direction by the rotation of the driven gear member, wherein the motor, the feed screw member and the lock bar are accommodated in parallel within the case member, characterized by an overload protection module configured to block the transmission of a driving force of the motor to the lock bar when an overload occurs in the course of the lock bar being advanced, wherein the driven gear member comprises a first driven gear member having a gear which is meshed with the driving gear member and a second driven gear member having the female thread, and the overload protection module comprises a torque limiter which is interposed between the first driven gear member and the second driven gear member, and wherein when an overload occurs in the lock bar, the first driven gear member is idled with respect to the second driven gear member.