In a reflection type angle of view transforming optical apparatus for transforming an angle of view in an image apparatus and so forth, sufficient strength can be provided and process is facilitated by using reflecting mirrors in a wide angle optical system. The reflection type angle of view transforming optical apparatus includes a primary mirror 8 having a reflecting surface provided in an axisymmetric form to reflect incident light 12 as primary reflected light 13, a secondary mirror 10 having a reflecting surface provided in an axisymmetric form about the same axis of rotational symmetry 9 as that of the primary mirror 8, opposed to the primary mirror 8 so as to reflect the primary reflected light 13 and to get secondary reflected light 14 for focusing on a view point, and a transparent case 11 to support the primary mirror 8 and the secondary mirror 10, and transmit the incident light 12.