To integrate the pressure controller and flowmeter compactly.

This device is equipped with a manometer which measures intake pressure, the flowmeter 67 which measures the flow rate from an outlet, and a flow rate control valve 32 which controls the flow rate. Then the housing 20 of the main body of the pressure controller is formed in a nearly columnar shape, the intake and manometer, and outlet and flow rate control valve are formed and mounted on the flank of the housing at mutually opposite positions, and connection paths which are formed in the housing and connect them are arranged. Consequently, the flowmeter 67 is integrally coupled and fixed at the housing upper part and a piston type pressure reduction valve is formed on the housing reverse surface side, so the depth of the pressure controller can be shortened and the device which is compact on the whole is obtained.