PURPOSE: To improve the overall efficiency of a maneuverable compressor assembly i.e., the ratio of driving energy and compressed gas amount by arranging a compressor of an exhaust gas turbocharger in a pressure line of a compressor driven by an internal combustion engine.

CONSTITUTION: Gas is sucked into an exhaust gas turbocharger 21 via an intake line 60 after being filtered in a filter 10. The supercharged gas is delivered to a compressor 50 driven by an internal combustion engine 40 via a pressure line 70. The exhaust gas from the internal combustion engine 40 is delivered to the exhaust gas turbocharger 21 via an exhaust gas pipe 30 and then discharged from an exhaust gas pipe 32. The gas in the compressor 50 is delivered to a pressure reservoir 80 with a safety valve 81 via a pressure line 72. The gas in the pressure reservoir 80 delivered to a pressure maintaining check valve 82 via a pressure line 75, and then delivered to a tap 83 via a pressure line 76. In this way, it is possible to improve the overall efficiency of the maneuverable compressor assembly.