An imaging apparatus which is not affected by diffraction phenomenon even if a molding optical element is not polished and therefore has a periodic streak, and can ensure a good image quality. The imaging apparatus forms a subject image on an imaging plane (6), where light receiving elements are arranged, by means of an imaging optical system (7). The imaging optical system (7) comprises a molding optical element (1) produced through a process for forming a periodic streak (2) on the optical surface, wherein, when a high brightness subject light having a brightness exceeding the saturation sensitivity of the light receiving element impinges on the imaging optical system (7), an unnecessary optical image (11) is formed, by the streak on the optical surface based on the high brightness subject light, in the region (10) of the subject image concerning the high brightness subject light, when there is no streak (2) on the optical surface, on the imaging plane (6).