Abstract: In a steering lock device used for a vehicle in which the locking member allows a steering shaft to rotate when an inner cylinder of a cylinder lock moves to ON position by the operation of a key, while the locking member locks the steering shaft when the key is withdrawn at a LOCK position, the steering lock device comprises a key lever disposed in the inner cylinder such that it can swing depending on the insertion and withdrawal of the key, an engaging portion disposed on the outer cylinder that engages the key lever when the inner cylinder is rotated from the ON position to the LOCK position by the key operation and a locking member disposed on the outer cylinder which retracts when the inner cylinder is positioned at the key withdrawal position, thereby unlocking the steering lock shaft, while protrudes when the key is withdrawn, thereby locking the steering shaft non rotatably.