WATER CLOSET

To suppress clogging of drainage pipes while realizing water saving.SOLUTION: A water closet according to an embodiment comprises a toilet body, a tank for storing flush water to be supplied to the toilet body, a drain valve device that opens and closes the drain port of the tank to perform toilet flushing by supplying the flush water from the tank to the toilet body, and a tank water supply control unit that controls water supply to the tank, wherein the tank water supply control unit performs additional water supply to the tank when toilet cleaning has not been performed for a predetermined time since the last time and increases the amount of wash water supplied from the tank to the toilet body at the next toilet flush.SELECTED DRAWING: Figure 3 【課題】節水化を実現しつつ排水配管のつまりを抑制すること。【解決手段】実施形態に係る水洗大便器は、便器本体と、便器本体へ供給する洗浄水を貯留するタンクと、タンクの排水口を開閉してタンクから便器本体への洗浄水の供給による便器洗浄を実施させる排水弁装置と、タンクに対する給水制御を行うタンク給水制御部とを備え、タンク給水制御部は、便器洗浄が前回実施されてから所定時間以上実施されない場合、タンクへの追加給水を行い、次回の便器洗浄においてタンクから便器本体へ供給する洗浄水の水量を増やす。【選択図】図３