To provide an engaging lock for a sliding door capable of being locked and released by simple operation even by a finger handicapped person in the engaging lock used for the sliding door.

The engaging lock for the sliding door comprises a surface-plate frame 2 and a cover installed onto the rear of the surface-plate frame 2, and an engaging lever 5 for engagement with an engaging shaft mounted on a door stop is set up rotatably between the surface-plate frame 2 and the cover. A knob 3 for rotating the engaging lever 5 is formed at a place displaced from the central point of the turn of the engaging lever 5, and the knob 3 is projected from the external surface of the surface-plate frame 2 and formed rotatably and slidably.