To set a fundamental opening and closing degree of a door, etc., on which a hinge is installed by an independent and single effect of the hinge and to realize automatic recovery to the fundamental opening and closing degree in moving from the fundamental opening and closing degree.

A fundamental position of a hinge is specified by giving inclination to a connecting surface of a hinge, and it is made possible to automatically recover the fundamental position (to be connected to recovery of a door, etc., to a fundamental opening and closing degree) against movement of the hinge from the fundamental position (connected to opening and closing of the door, etc.), by an effect due to the inclination of the connecting surface of the hinge by setting the fundamental opening and closing degree of the door, etc., on which this hinge is installed.