An EGR
system includes a high-pressure EGR passage that provides communication between an
exhaust pipe, at a portion upstream of a
turbine of a
turbocharger, and an intake
pipe, at a portion downstream of a compressor; a low-pressure EGR passage that provides communication between the
exhaust pipe, at a portion downstream of the
turbine, and the intake passage, at a portion upstream of the compressor; and an
exhaust gas catalyst provided upstream of a position at which the low-pressure EGR passage is connected to the
exhaust pipe. When an
internal combustion engine is in the transitional state from the low-load operating state to the high-load operating state (S303), if incomplete
combustion is detected in the
internal combustion engine (S304) and the
bed temperature of the
exhaust gas catalyst is lower than the reference temperature (S305), the high-pressure EGR gas amount is made larger than the prescribed high-pressure EGR gas amount determined based on the operating state of the
internal combustion engine (S306). Thus, an excessive decrease in the intake
air temperature is suppressed, and therefore occurrence of incomplete
combustion is suppressed.