Abstract: There is provided a bathtub apparatus capable of satisfactorily detecting an electrocardiographic signal even in a state where water is being discharged into a bathtub by a water discharge device. The present invention is a bathtub apparatus (1) including a bathtub main body (2), a water discharge device (8) that discharges water toward inside of the bathtub main body and is provided above a first inner wall surface (2a) forming a short side of the bathtub main body, and electrodes (4a, 4b, 4c) attached to the bathtub main body to detect an electrocardiographic signal of a bathing person, where the electrodes are arranged on an inner wall surface of the bathtub main body, and are arranged closer to the first inner wall surface than a position (P) where water discharged from the water discharge device hits a water surface of the water stored in the bathtub main body.