In an internal combustion engine in which an anodic oxide film (10) is formed on part or all of a wall surface facing a combustion chamber, the anodic oxide film (10) has a thickness of 30 μm to 170 μm, the anodic oxide film (10) has first micropores (1a) having a micro-size diameter, nanopores having a nano-size diameter and second micropores (1b) having a micro-size diameter, the first micropores (1a) and the nanopores extending from a surface of the anodic oxide film (10) toward an inside of the anodic oxide film (10) in a thickness direction of the anodic oxide film (10) or substantially the thickness direction, the second micropores (1b) being provided inside the anodic oxide film (10), at least part of the first micropores (1a) and the nanopores are sealed with a seal (2) converted from a sealant (2), and at least part of the second micropores (1b) are not sealed.