An engine system (1, 1a, 1c) comprising: an engine body; an intake channel for supplying intake air to the engine body; an exhaust channel through which exhaust gas discharged from the engine body flows; a turbocharger including a turbine disposed in the exhaust channel and driven by energy of the exhaust gas discharged from the engine body, and a compressor disposed in the intake channel and driven coaxially with the turbine; and an intake bypass device for guiding a part of compressed intake air compressed by the compressor to flow to an upstream side of the turbine bypassing the engine body, wherein the intake bypass device includes a bypass channel connecting a downstream side of the compressor in the intake channel and an upstream side of the turbine in the exhaust channel, a bypass valve disposed in the bypass channel and configured to control a flow of the compressed intake air in the bypass channel, and a heating unit for heating the compressed intake air flowing through the bypass channel, the heating unit being disposed on a downstream side of the bypass valve in the bypass channel, wherein the heating unit is configured to utilize the exhaust gas discharged from the engine body as a heat source for heating the compressed intake air flowing through the bypass channel, characterized in that the heating unit comprises a turbine housing of the turbine forming at least a part of an inner wall surface of the bypass channel, in a partial section of the bypass channel. an engine body; an intake channel for supplying intake air to the engine body; an exhaust channel through which exhaust gas discharged from the engine body flows; a turbocharger including a turbine disposed in the exhaust channel and driven by energy of the exhaust gas discharged from the engine body, and a compressor disposed in the intake channel and driven coaxially with the turbine; and an intake bypass device for guiding a part of compressed intake air compressed by the compressor to flow to an upstream side of the turbine bypassing the engine body, wherein the intake bypass device includes a bypass channel connecting a downstream side of the compressor in the intake channel and an upstream side of the turbine in the exhaust channel, a bypass valve disposed in the bypass channel and configured to control a flow of the compressed intake air in the bypass channel, and a heating unit for heating the compressed intake air flowing through the bypass channel, the heating unit being disposed on a downstream side of the bypass valve in the bypass channel, a bypass channel connecting a downstream side of the compressor in the intake channel and an upstream side of the turbine in the exhaust channel, a bypass valve disposed in the bypass channel and configured to control a flow of the compressed intake air in the bypass channel, and a heating unit for heating the compressed intake air flowing through the bypass channel, the heating unit being disposed on a downstream side of the bypass valve in the bypass channel, wherein the heating unit is configured to utilize the exhaust gas discharged from the engine body as a heat source for heating the compressed intake air flowing through the bypass channel, characterized in that the heating unit comprises a turbine housing of the turbine forming at least a part of an inner wall surface of the bypass channel, in a partial section of the bypass channel.