CLEANING WATER TANK DEVICE AND WATER CLOSET WITH CLEANING WATER TANK DEVICE

PROBLEM TO BE SOLVED: To provide a cleaning water tank device capable of preventing what is called "cleaning before storage of water" in which cleaning water is supplied to a toilet bowl to perform cleaning in an unprepared state while cleaning water is not stored in a cleaning water tank by an amount needed to clean the toilet bowl, with a simple structure.SOLUTION: A cleaning water tank device 18 of the present invention includes drain valve 60, and 62 which open and close a drain port 22a of a water storage tank 22, operation parts 46, and 48 which open the drain valves, and a connection part which connects the operation part and drain valves in a disconnectable state. The connection part 72 includes connection switching means 90, 92, 94, and 96 which perform switching to connect the operation part and drain valves so that the operation parts can open the drain valves when the water level in the water storage tank is equal to or higher than a predetermined water level WL1 corresponding to the amount of cleaning water needed for toilet bowl cleaning, and to disconnect the operation part and drain valves so that the operation part becomes unable to open the drain valves when the water level in the water storage tank is lower than the predetermined water level WL1.