To provide a screen cleaning device which can completely remove underwater suspended matters adhered onto a water intake for water jet so as to refresh the device in a water jet propelled boat.

In a water jet propelled boat, a screen 7 composed of movable belt shaped bars 7a, and of a screen frame 7b, is mounted to whole the surface of a jet water intake 8 provided for the bottom of the boat. By letting the movable belt shaped bars 7a be bent downward, and projected out of the screen frame 7b, wastes such as underwater suspended matters adhered onto the screen 7, causing the screen to be clogged, can be peeled off, and removed by a current, and the screen 7 can thereby be refreshed while the boat is sailing.