An air exchange device, in particular for an inner room of a building, with an exhaust air flap for the selective closing of an exhaust air inlet for air flowing out of the inner room and with a supply air flap for the selective closing of a supply air outlet for air flowing into the inner room, wherein an actuation mechanism driven by a drive pinion of a single electric motor is provided for the exhaust air flap and the supply air flap, wherein the actuation mechanism comprises the following features: - the supply air flap is connected to a supply air flap rotation shaft in such a manner that it is rotatable, limited by respective stopping regions, between a supply air flap closing position and a supply air flap opening position, - the exhaust air flap is connected to an exhaust air flap rotation shaft in such a manner that is rotatable, limited by respective stopping regions, between an exhaust air flap closing position and an exhaust air flap opening position, characterized in that - the rotational angle of the supply air flap between the supply air flap closing position and the supply air flap opening position is different from the rotational angle of the exhaust air flap between the exhaust air flap closing position and the exhaust air flap opening position, - the drive pinion of the electric motor engages at a pinion region of the exhaust air flap rotation shaft, if the rotational angle of the supply air flap between the supply air flap closing position and the supply air flap opening position is less than the rotational angle of the exhaust air flap between the exhaust air flap closing position and the exhaust air flap opening position, or the drive pinion of the electric motor engages at a pinion region of the supply air flap rotation shaft, if the rotational angle of the supply air flap between the supply air flap closing position and the supply air flap opening position is greater than the rotational angle of the exhaust air flap between the exhaust air flap closing position and the exhaust air flap opening position, and - the supply air flap rotation shaft is detachably connected with the exhaust air flap rotation shaft in such a manner that a clearance is provided between the supply air flap rotation shaft and the exhaust air flap rotation shaft which ensures a rotatability of the exhaust air flap shaft with respect to the supply air flap shaft. - the supply air flap is connected to a supply air flap rotation shaft in such a manner that it is rotatable, limited by respective stopping regions, between a supply air flap closing position and a supply air flap opening position, - the exhaust air flap is connected to an exhaust air flap rotation shaft in such a manner that is rotatable, limited by respective stopping regions, between an exhaust air flap closing position and an exhaust air flap opening position, - the rotational angle of the supply air flap between the supply air flap closing position and the supply air flap opening position is different from the rotational angle of the exhaust air flap between the exhaust air flap closing position and the exhaust air flap opening position, - the drive pinion of the electric motor engages at a pinion region of the exhaust air flap rotation shaft, if the rotational angle of the supply air flap between the supply air flap closing position and the supply air flap opening position is less than the rotational angle of the exhaust air flap between the exhaust air flap closing position and the exhaust air flap opening position, or - the supply air flap rotation shaft is detachably connected with the exhaust air flap rotation shaft in such a manner that a clearance is provided between the supply air flap rotation shaft and the exhaust air flap rotation shaft which ensures a rotatability of the exhaust air flap shaft with respect to the supply air flap shaft.