PURPOSE: To reduce air resistance due to a shutter upon ventilation and prevent freezing of the shutter in winter, in a simultaneous air supply and exhaust type ventilating device effecting air supply and air exhaust simultaneously.

CONSTITUTION: An air discharge vane 2, sucking air from a room side suction port 4 and discharging air to the outside of a room, an air supplying vane 3, sucking air in the outside of the room and discharging air to the outside of the room through a room side discharge port 7, a motor 1 for driving the air discharge vane 2 and the air supplying vane 3, and the like are accommodate in the body 8 of the title device. A louver 13 is provided at the room side of the body 8 and, further, shutters 9a, 9b are provided between the louver 13 and the room side suction port 4 as well as the room side discharge port 7. The shutters 9a, 9b are opened and closed by a pull-string device. The shutters 9a, 9b are provided on the room side of the body 8 whereby air resistance upon ventilation is reduced and the freezing of the shutters 9a, 9b in winter can be prevented.