An engine system with a thermal storage device is capable of efficiently supplying heat from a thermal storage device to an internal combustion engine. The engine system (1) equipped with the thermal storage tank (100) supplies the hot water stored in the thermal storage tank (100) to a cylinder head (20a) of the internal combustion engine (20) before the starting thereof. At this time, an electronic control unit (90) sets a target value of the temperature of the internal combustion engine (20) at the start of the hot water supply in such a manner that the lower the temperature of the internal combustion engine (20), the lower does the target value become. As a result, a variation in combustion states between cylinders can be suppressed at the starting of the internal combustion engine (20).