A turbocharger (1) includes a turbine wheel (3) driven by exhaust gas, first and second compressor wheels (4, 5) coaxially coupled to the turbine wheel (3) via a shaft member (6), a compressor housing (8) accommodating the first and second compressor wheels (4, 5) and having defined therein a communication passage (17) through which air compressed by the first compressor wheel (4) flows to the second compressor wheel (5), and an electric motor (11) arranged in the communication passage (17) and using the shaft member (6) as a rotation shaft thereof.