PURPOSE: To facilitate piping work and to enhance reliability of junctions in the construction of the entitled devices, by employing a simple structure of connecting the pipings of manifolds for suction and exhaust with plural gas treating devices with elastic bodies airtightly.

CONSTITUTION: Piping manifolds 55 are placed above plural gas treating devices 51 each fixed to a bottom plate 53 with fixing bolts 52 having a suction hole 51A and an exhaust hole 51B, with an elastic body 54, such as a spring interposed, and connected airtightly with each device 51 with rubber packing 60, 61 between. Said manifold 55 is constituted of an upper plate 55A, a lower plate 55B in parallel to each other, and a partition plate 55C rectangular to them, located between the holes 51A and 51B to provide a suction path 57 and an exhaust path 58 each connected with the holes 51A, 51B, respectively. A heat medium path 59 is formed above the partition plate 55 to cool the devices 51 through the manifolds 55.