To provide a bathroom external wall opening/closing unit striking a balance between open outdoor bath mood bathe and bathe securing privacy and adjusting the temperature decrease of the bathroom in winter in the same extent as the conventional bathroom and shortening the completion time of execution even when applied to a bathroom of an ordinary house, capable of receiving daylight and air ventilation of the bathroom without opening/closing the opening/closing wall and provide a house so that the opening/closing wall can receive daylight into a room adjacent in the adjacent direction for the bathroom by using the bathroom external wall opening/closing unit.

A laterally movable opening/closing wall 1 constituting the external wall of a bathroom 10 and a frame body 5 in which the opening/closing wall 1 is fitted, guiding the lateral movement of the wall 1, a drive section disposed in the frame body 5 and driving the wall 1 laterally, and control parts 22, 22 controlling the movement of the drive section, are provided. A window 6 is provided in the opening/closing wall 1 so as to face a window provided on the external wall of the room 11 adjacent to the bathroom 10 when the wall 1 is opened.