To achieve simplification of a circuit and control, cost reduction, and improvement of workability.

Vacuum generators 24, 26 is characteristically provided with a switcher 87 which shuts off a flow for discharging discharge air from a pneumatic actuator device 29 to the outside through a discharge port 78 from receiving ports 45, 46 while compressed air from a pneumatic source is supplied from input ports 41, 42 through the receiving ports 45, 46 to the pneumatic actuator device 29, and meanwhile shuts off a flow for supplying compressed air from the pneumatic source to the pneumatic actuator device 29 through the receiving ports 45, 46 from the input ports 41, 42 while the discharge air from the pneumatic actuator device 29 is discharged from the receiving ports 45, 46 through the discharge port 78 to the outside.