To provide an automatic water-stopping device which enables sure water stoppage with a simple configuration, is reduced in size as a whole, and prevents waste of water resources.

The automatic water-stopping device 1 includes a case 10 having a feed-water inlet, a feed-water discharge port, and a channel, a valve body 20 having a valve that opens and closes the channel, a hook 30 which is supported rotatably on the case 10 and prevents an axial motion of the valve body 20, a spring 60 which continuously energizes the valve body 20 in the direction of plugging the valve body 20, and a spring 70 which energizes the hook 30 rotatably in the direction of engaging it with the valve body 20.