BATHROOM UNIT, AND METHOD FOR INSTALLING BATHROOM UNIT

PROBLEM TO BE SOLVED: To provide a bathtub unit which can dispose a bathtub and a washing floor in an accurate positional relationship, and to provide a method for installing the bathroom unit.SOLUTION: The bathtub unit includes: a washing place floor pan having a washing place floor drain port for draining water of the washing place; a bathtub having a bathtub drain port for draining water in the bathtub; and a drain trap having a washing place side water introducing port for receiving water drained from the washing place and a bathtub side water introducing port for receiving water drained from the bathtub to drain both the water of the washing place floor and the water in the bathtub to a drain pipe. A relative position of the washing place side water introducing port and the bathtub side water introducing port of the drain trap is fixed, the washing place side water introducing port is connected to the washing place floor drain port in an unrotatable manner, and the bathtub side water introducing port is connected to the bathtub drain port in an unrotatable manner, so that the position of the bathtub can be determined to the washing place floor pan.