To inexpensively and efficiently exhaust noncondensing gas.

A gas separator 26 is connected to an absorber 4 via a first gas exhaust pipe 25, a gas storage chamber 28 is connected to the gas separator 26 via a second gas exhaust pipe 27, and a gas exhaust device 30 comprising two palladium cells 29 and 29 is connected to the gas storage chamber 28. An absorbing liquid pump 12 and an upper part of the gas separator 26 is connected via a seventh piping 31, a lower part of the gas separator 26 and the absorber 4 is connected via a liquid return pipe 32, and it is composed such that gaseous hydrogen in the noncondensing gas extracted and separated by the gas separator 26 is permeated through the palladium cells 29 and discharged to the atmosphere. A second gas exhaust piping 27 and the absorbing liquid pump 12 are separably connected via a piping 34 for pressurization, and a pressure in the gas storage chamber 28 is increased by using the absorbing liquid pump 12.