An internal combustion engine, comprising, a cylinder head; a rotational shaft supported by said cylinder head and lubricated; a head cover arranged on said cylinder head; an end member arranged at an axial end of said rotational shaft; a first chamber defined at least by said cylinder head and said end member and accommodating said rotational shaft; a second chamber defined at least by said head cover and having an opening to said first chamber; and a baffle integrally formed with said end member and extending in an axial direction of said rotational shaft between said opening and said rotational shaft in a radial direction of said rotational shaft.