To provide a waterproof pan for a bathroom facilitating installation by carrying in the waterproof pan in the folded state while making the most of the merits of a divided type and an integrated type.

This waterproof pan for the bathroom is provided with a bathtub installation part for installing a bathtub, and a washing place part formed independently of the bathtub installation part, with the upper face forming a washing place. The adjacent peripheral sidewalls of the bathtub installation part and washing place part are connected by an openable/closable hinge member, and the bathtub installation part and the washing place part can be set in both states of an installed state and a folded state by the opening/closing position of the hinge member. The hinge member is formed of a plastic hinge of almost the same length as the adjacent peripheral sidewalls of the bathtub installation part and washing place part, and has both functions of a connecting function and a waterproofing function.