ENGINE COMBUSTION CHAMBER STRUCTURE AND INNER WALL STRUCTUREOF FLOW PATH

There is provided a structure of a combustion chamber for an engine which enhances a thermal efficiency of the engine to enhance a fuel efficiency, and an inner wall structure of a flow path through which an intake gas or an exhaust gas of the engine flows. The structure of the combustion chamber for the engine includes a heat-insulating member 1 including a heat-insulating layer 3 formed on the surface of an engine constituting member 21 constituting the combustion chamber for the engine and a dense surface layer 2 formed on the surface of the heat-insulating layer 3. Furthermore, the heat-insulating layer 3 includes ceramic and/or glass, and has pores of pore diameters of 10 to 500 nm and a porosity of 10 to 99%, and the dense surface layer 2 includes ceramic and/or glass and has a porosity of 5% or less.