A supercharged internal combustion engine of the present invention is provided with a turbocharger (18) having a compressor (18b) in an air intake passage (24), a communication passage (52) connected between an upstream-side portion of the air intake passage (24) on the upstream side of a compressor impeller (18b3) and an internal space (90) of the internal combustion engine (10), and an oil supply apparatus (96, 98, 100) that supplies oil to an internal passage in the compressor (18) through which intake air flows. When a deposit buildup operation condition under which there is a concern of a buildup of a deposit in the compressor (18) is met, the oil supply apparatus (96, 98, 100) increases the amount of oil supplied to the internal passage compared with the amount of oil supplied when the deposit buildup operation condition is not met.