An occlusion evaluation apparatus capable of evaluating a masticatory ability depending on an occlusal geometry of teeth, reads three dimensional data of geometries of maxillary molar teeth (1, 2, 3, 4) and mandibular molar teeth (5, 6, 7, 8), and specifies a geometry of a flexion space (Va) defined by a plane (Sa) which includes two adjacent contact points (Pa) between the maxillary molar teeth (1, 2, 3, 4) and mandibular molar teeth (5, 6, 7, 8) and which is perpendicular to the occlusal plane, the occlusal surfaces of the maxillary molar teeth (1, 2, 3, 4,) and the occlusal surfaces of the mandibular molar teeth (5, 6, 7, 8).
