Patent ID: 8571436

Claim:
A gas transfer unit comprising: a transfer path forming member in which a gas transfer path through which a gas sucked from a suction port is transferred is formed, and which comprises: a first transferring portion which extends along a first gas transfer direction; a bent portion which is connected to a downstream side of the first transferring portion in the gas transfer direction, and which is bent toward a second gas transfer direction that is inclined to the first gas transfer direction; a first exhaust port which is placed downstream from the bent portion and on an extension line of the first gas transfer direction, and through which a gas is able to be exhausted; and a second exhaust port which is placed downstream from the bent portion and on an extension line of the second gas transfer direction, and through which a gas is able to be exhausted; a gas transferring member which has rotatable transfer vanes, and which transfers a gas in the gas transfer path by rotation of the transfer vanes; and a gas purifying member which is placed correspondingly to the second exhaust port, and which purifies the gas passing through the second exhaust port, wherein, in a case where exhaustion is performed through the first exhaust port, the transfer vanes are rotated at a first rotation number, and, in a case where exhaustion is performed through the second exhaust port, the transfer vanes are rotated at a second rotation number which is higher than the first rotation number.