PURPOSE: To prevent cooled remaining water in a water discharge piping from being splashed to a shoulder, etc., of a bathing person at the time of initial water discharge, in the water discharge bathtub which can execute shoulder beating water discharge.

CONSTITUTION: In the shoulder beating water discharge bathtub A in which a bath hot water circulating flow passage 13 consisting of a water absorption piping 11 and a water discharge piping 12 is provided between a bathtub main body 10 and a circulating pump P, and also, the tip discharge port of the water discharge piping 12 is positioned in the upper part than the hot water filled surface in the bathtub main body 10, and bath hot water can be discharged from the tip discharge port, a drain piping is allowed to branch and formed through a three- way valve in the halfway part of the water discharge piping, and the three-way valve is placed in a little lower position than the circulating pump P. In the case of executing shoulder beating water discharge, remaining water in the water discharge piping is discharged from the drain piping by executing a switching operation of the three-way valve in advance, and also, since the three-way valve is positioned in a little lower position than the circulating pump, remaining water in the water discharge piping is all drained, and accordingly, in the case of executing shoulder beating water discharge again, remaining water in the water discharge piping does not come out.