To provide a sliding door lock wherein a hook member 5 is projected from the end face of a door 1 and is hooked on a frame body 2 side to be automatically changed into a locking state by making a magnet 6 disposed on the base end of the member 5 and a magnet 3 disposed on the base of the frame body 2 repulse each other when the end face of the door approaches the end face of the body 2 when the door 1 is closed.

The rotatable sickle hook member 5 is provided to the door 1 side, the hook member 5 is projected from the end face of the door 1 so that it can be hooked on the frame body 2 side. The magnets 6 and 3 making the magnetic repulsion to each other are respectively arranged to the base section of the hook member 5 and the end of the frame body 2.