To provide a single lever cock with a click mechanism capable of easily mounting the click mechanism generating the click feeling in adjusting the volume of water without occupying a wide mounting space.

In this single lever clock comprising an operation lever 28, a lever shaft 64 operated integrally with the operation lever 28, and a rotary guide 50 of the lever shaft 64, and adjusting the volume of water and a temperature by sliding and operating a movable valve element 46 to a fixed valve element 42 by transmitting the vertical rotational operation and the lateral rotational operation of the operation lever 28 to the movable valve element 46, the click mechanism 74 is mounted between the rotary guide 50 and a driving part 48 of the movable valve element 46 to generate the click feeling at a predetermined position in the vertical rotational operation of the operation lever 28.