A turbocharging system for use with an internal combustion engine, which includes an exhaust gas feeding passage configured to feed exhaust gas of an internal combustion engine to a turbine unit; an exhaust gas passage configured to release the exhaust gas discharged from the turbine unit outside of the turbocharging system; an intake air passage configured to feed intake air into the compressor unit; a compressed air passage configured to feed compressed air discharged from the compressor unit to the internal combustion engine; an intercooler configured to cool the compressed air flowing through the compressed air passage; and an LPL-EGR passage configured to recirculate at least a part of the exhaust gas flowing through the exhaust gas passage, into the intake air passage, wherein the compressed air passage is provided with a cyclone-type collecting device arranged upstream of the intercooler to collect foreign substances contained in the compressed air.