Exhaust port structure of internal combustion engine

In an exhaust port structure in an internal combustion engine, a cylinder head has a cylinder head body and a cylindrical exhaust port liner. The exhaust port liner is partially supported at a plurality of points on the cylinder head body , and a heat-insulating layer exists around the exhaust port liner. Thus, it is possible to inhibit the propagation of heat from the exhaust port liner to the cylinder head body as much as possible.