To select the temporarily installed height of a bathtub body over a plurality of stages and to stabilize the temporarily installed state thereof.

This footrest device is equipped with a pair of the front and rear up-and-down direction holding pillar members 11, 11, 21 and 21 attached to the bathtub body 70 on the sides of the front and rear end parts thereof so as to be mutually joined as left and right sets (by connection levers 12 and 22) and also equipped with left and right sets of front footrest frame members 31 and 31, and rear footrest frame members 41 and 41 which are pivotally supported between the left and right holding pillar members 11, 11, 21, 21 (by pivot support shafts 32 and 42) in a pivotally revolvable manner in a left and right connected state (by connection levers 33 and 43) and have a plurality of holding footrest surfaces 34, 35, 44 and 45 for selectively holding the bathtub body 70 at different height positions H1 and H2 at every required pivotal revolving angle.