POSITIVE CRANKCASE VENTILATION VALVE MOUNTING STRUCTURE

A PCV valve mounting structure which releases freezing of a PCV valve promptly is provided. A PCV valve mounting structure is provided with a resin cover forming an internal space portion between the resin cover and a cylinder head of an internal combustion engine, a valve mounting through hole formed at the resin cover, a PCV valve including a valve case portion inserted through the valve mounting through hole from outside the resin cover, and a metal fixture threadedly engaged, from inside the resin cover, with the valve case portion inserted through the valve mounting through hole, at least part of the metal fixture being exposed to the internal space portion.