To make washable and disinfectible foods and the like effectively by attaching a device that electrolyzes water in a tank and a means that forms water circulation in the water tank.

A unit 20 for electrolysis is a device for electrolyzing water in the tank to which the device is attached. The unit consists of a cylindrical anode 22 that is attached penetrating nearly the center of the main body 21 from up to down and a cathode 23 that is attached as it faces the main body so as to bind the main body 21 forward and backward. A cover 24 is screwed to the upper side of the main body 21. Unit 30 mounts a device to form a water circulation in a water tank to which the main body is attached and an attaching device that attaches the main body to the water tank. The unit consists of pipe 32 for taking water that penetrates the main body 31 from up to down, pipe 33 for draining water and attaching part 39.