To provide a residual liquid discharging device which efficiently and inexpensively discharges a residual liquid, by a simple constitution.

When a shower is used, a stream pressure in a shell 50 is sensed by a stream pressure sensing plate 52C, and an opening/closing valve 52A closes a water draining port 54 by resisting the urging force of a coil spring, and a state wherein the water draining port 54 is closed by the stream pressure which presses the stream pressure sensing plate 52C, is maintained. In the meantime, when the shower is not used, the coil spring turns the opening/closing valve 52A in the opening direction by resisting a water pressure to a shower head, and the water draining port 54 is opened, and remaining hot water is discharged from the water draining port 54.