According to one embodiment, a gas recovering apparatus includes a casing and a tube. The casing is provided with an inlet through which a gas flows in, a first outlet for discharging a first gas containing a gas to be recovered of the gas, and a second outlet for discharging a second gas other than the first gas of the gas. The casing is evacuated via the first outlet. The tube is provided in the casing from the inlet to the second outlet, and has a high permeability to the first gas and a low permeability to the second gas.