PURPOSE: To provide an easy and less-expensive formation of a suction port in a ventilation fan for a bath-room to be installed in a wall of a general house and for discharge moisture and steam in the bath-room in concurrent with an installation of the ventilation fan for the bath-room without restriction of the installing location of the suction port.

CONSTITUTION: Flanges 6a and 6b are disposed at an upper end and a lower end of a side surface 1a of a frame 1. The width of the opening of a vertical wall 2 is so set that a longer size of the flange 6a or 6b is added to the width of the frame 1 and then the ventilation fan for the bath-room is fixed, resulting in that the suction port 7 having the same height of that of the frame 1 and the same width of longer one of those of the flange 6a or 6b and then ventilation within the bath room can be positively carried out through this suction port. As the sizes of the flanges 6a and 6b are of 1/2 of the height of the frame 1 and the flanges are disposed with hinges, it is possible to bend the flanges at the hinges in the bath-room having an existing suction port, closely contacting them to the frame 1 and integrally fix the frame 1.