To provide an equipment, in which the position of the installation of a control switch is set freely because drainage operation is conducted electrically by utilizing the buoyancy of a hollow circular float valve disc and the magnetic force of an electromagnet and a permanent magnet, not mechanical operation by the revolution of a lever and which is operated easily and is sanitary and has excellent consistency with electrical equipments for other toilets such as a shower toilet being increasing recently and also superior appearance.

An electromagnet 1 is installed onto the inside diametral surface of a drain inlet 10' for a water storage tank, a permanent magnet 2 is, on the contrary, fitted to the bulging section of a circular float valve disc 3 freely seated from an upper section, and the circular float valve body 3 is brought to the state, in which the float valve body 3 is not floated even when water is supplied, because these magnetic force exceeds the buoyancy of the circular float valve body 3, but the electromagnet repels because the magnetic force of the same magnetic pole as the permanent magnet is generated in the electromagnet by turning an electric switch on by a user, and the circular float valve disc 3 is separated from the drain inlet 10' and opened.