An object of the invention is to provide an engine device which can prevent electric parts provided in an exhaust gas purification device from breaking down due to heating. An engine (1) is provided with an exhaust gas treatment device (2) which treats exhaust gas. The exhaust gas treatment device (2) is provided with electric parts (44, 51-53) which detect a state of the exhaust gas purification device (2). The engine (1) is provided with a cooling water circulation mechanism which circulates cooling water for the engine (1). Further, the electric parts (44, 51-53) are arranged in an outer side of the exhaust gas purification device (2) on an extension in a longitudinal direction of the exhaust gas purification device (2).