To provide a ventilating system which can properly perform the ventilation of air inside and outside a room.

A sidewall 104 connects an indoor ceiling wall 108 with an upper wall, and these walls form an attic space. A bulkhead 112 demarcates the space on the ceiling into the first space near an entrance opening 115 and the second space near a balcony opening. An opening 126 for ventilation is provided in the bulkhead 112 so that it may connect the first space with the second space. The first indoor intake port 134 connects the first space with a living room. The second indoor intake port 136 connects the second space with the living room, a kitchen, a bathroom, a toilet room, and a washroom. The first outdoor intake port 130 connects the outside of the room on the side of an entrance opening 115 with the first space. The second outdoor intake port 132 connects the outside of the room on the side of the balcony opening with the second space.