PURPOSE: To solve the problems with a vicious duplication occurring when a key is missed or stolen by providing a detachable type lock capable of removing a whole lock maid body from a door panel.

CONSTITUTION: A head part 3 of a lock main body 5 is close-fitted fixedly into an inserting hole 2 of a door panel 1, and a flange part 4 of the lock main body 5 is made in contact with the front surface la of the door panel 1. Also a lock tube body 9 is close-fitted to the body part 8 of the lock main body 5, and fixed to the rear end part of a rotor 7. Then the receiving hole 11 of the lock tube body 9 is installed in the receiving metal plate 12 installed fixedly to a fixed frame body 10, and an inserting hole 2 and the receiving hole 11 are formed in a non-complete round shape in which a difference is set between lengths in short- and long-axis directions crossed at a specified angle. In addition, the cross section external forms of the head part and the lock tube body are formed identical, and the lock tube body 10 is rotated with a key by a specified angle so as to engage the front end surface 9a of the lock tube body 9 with the rear surface 12a of the receiving metal plate 12 by an amount of dimensional difference.