An engine apparatus includes an engine and an exhaust gas purifier. The engine includes an intake manifold and an exhaust manifold. The exhaust gas purifier is configured to purify exhaust gas of the engine and disposed on an upper side of the engine through a mounting base. The mounting base includes an intake-side bracket and an exhaust-side bracket, which support one end of the exhaust gas purifier. One end of the intake-side bracket and one end of the exhaust-side bracket are fastened to each other. The other end of the intake-side bracket and the other end of the exhaust-side bracket are coupled to the engine side.