Hot water supplying device

The present invention relates to a hot water supplying device disposed between a water heater and a water output device, such as a faucet or a showerhead, which comprises a water drainage tank, a water storage tank, a water pump, and a control device. The control device may set the time based on the setting or in other time arrangement to pump out the accumulated water in the water inlet pipe of the water output device by the water pump, so that the accumulated water will not be drained while opening the water output device; and, the hot water switch and the water storage switch turned on together with the water output device will allow the hot water in the water heater and the water in the water storage tank to enter the water drainage tank, and then enter the water output device after mixing in the water drainage tank and to be discharged. Since the diameter of the water storage pipe is smaller than that of the water outlet pipe of the water heater, the water after mixing is still approximately warm water.