A steering lock device, used with a vehicle shift lever that is shifted to a parking position and a non-parking position, the steering lock device comprising: a camshaft including a shaft portion having an axis, a lock actuation cam that radially projects from a first position of the shaft portion in an axial direction, and a projection that radially projects from a second position of the shaft portion that differs from the first position in the axial direction, wherein the camshaft is rotated about the axis when a key cylinder is operated by a mechanical key; a housing that rotatably accommodates the camshaft, the key cylinder is coupled to the housing, the housing includes an interlock attachment portion configured to attach a key interlock unit that prohibits removal of the mechanical key from the key cylinder unless the shift lever is shifted to the parking position; and a lock bar that is moved by the lock actuation cam in a locking direction or an unlocking direction when the camshaft is rotated, wherein when the lock bar is moved in the locking direction, the lock bar engages a steering shaft to lock the steering shaft, and when the lock bar is moved in the unlocking direction, the lock bar is disengaged from the steering shaft to unlock the steering shaft, characterized in that when the lock bar locks the steering shaft, the camshaft is configured so that the projection that includes a cam-shaped interlock cam that actuates the key interlock unit is separated from the shaft portion if a load exceeding a predetermined strength acts on the projection of the camshaft, wherein the predetermined strength rotates the lock actuation cam to disengage the lock bar from the steering shaft. a camshaft including a shaft portion having an axis, a lock actuation cam that radially projects from a first position of the shaft portion in an axial direction, and a projection that radially projects from a second position of the shaft portion that differs from the first position in the axial direction, wherein the camshaft is rotated about the axis when a key cylinder is operated by a mechanical key; a housing that rotatably accommodates the camshaft, the key cylinder is coupled to the housing, the housing includes an interlock attachment portion configured to attach a key interlock unit that prohibits removal of the mechanical key from the key cylinder unless the shift lever is shifted to the parking position; and a lock bar that is moved by the lock actuation cam in a locking direction or an unlocking direction when the camshaft is rotated, wherein when the lock bar is moved in the locking direction, the lock bar engages a steering shaft to lock the steering shaft, and when the lock bar is moved in the unlocking direction, the lock bar is disengaged from the steering shaft to unlock the steering shaft, characterized in that when the lock bar locks the steering shaft, the camshaft is configured so that the projection that includes a cam-shaped interlock cam that actuates the key interlock unit is separated from the shaft portion if a load exceeding a predetermined strength acts on the projection of the camshaft, wherein the predetermined strength rotates the lock actuation cam to disengage the lock bar from the steering shaft.