A lubricating layer having wear resistance and reliability on the wear resistance, and a compressor including a lubricating layer are provided. The compressor may include a lubricating layer coated on a frictional portion between a rotational shaft and a bearing. The lubricating layer may include at least one metal phase selected from a group consisting of Titanium (Ti); and Copper (Cu), Cobalt (Co), Nickel (Ni), and Zirconium (Zr), and may be a composite structure of amorphous and nanocrystalline materials.

In a spark ignition engine, a thermal insulation thin layer is formed over a wall surface, facing an inside of a combustion chamber, of a base material forming the combustion chamber, and for a thermal conductivity [W/(m.Math.K)], a thermal diffusivity [mm.sup.2/s], and a thickness L [m] of the thermal insulation thin layer, L16.7 and L207.4().sup.0.5 are satisfied. With such a configuration, a heat loss Q_total escaping from gas in a cylinder to the wall of the combustion chamber over all strokes can be reduced, and the thermal efficiency can be improved without inducing degradation of knocking due to an increase in an amount of heating Q_intake of the gas in the cylinder during an intake stroke.