Abstract: A burglar proof lock for instance for a door, trunk lid, ignition switch, steering column, etc. of a motor car and of the type which is formed with a rotatable lock cylinder comprising several latch plates which in a predetermined order become partly expelled in the radial direction from the lock cylinder when the key is removed from the lock cylinder. In the expelled position, the lock plates lockingly engage a latch sleeve formed with several inner, annular grooves adapted to receive the latch plates of the lock cylinder in the locked condition of the lock. The lock cylinder can rotate freely in the latch sleeve but can not be moved axially in relation to said latch sleeve in such locked condition.