A fan with failure detecting function includes a power input terminal, a current limiting resistor, a light emitting diode, and a fan motor. Next, a connection member is mounted, one end of the connection member is abutted to an end portion of the face plate of the hollow frame member. At the start of regeneration, each adsorber is decompressed down to atmospheric pressure, then brought back up to the low pressure by impure nitrogen. The first level decoder generates soft information.