An electric steering lock device has a lock body to be installed in a mounting hole part of a steering column post of a vehicle, a drive part which generates a rotation drive power, a rotation shaft to be rotated by the rotation drive power of the drive part through a gear mechanism, a lock stopper to be screwed with the rotation shaft to move axially by rotating of the rotation shaft, a lock bar which moves between a lock position for locking a steering shaft by movement of the lock stopper and an unlock position for unlocking the steering shaft, and a bush. The bush has a load receiving part to receive thrust loading of the rotation shaft at least at one side of the rotation shaft, an installation claw part to be installed by inserting in a hole part of the lock body, and a bearing claw part to receive radial load by fitting to be slidably rotatable with an external diameter of the rotation shaft.