An optical apparatus includes a cam barrel configured to hold an optical member, which is movable back and forth along a first optical axis, on an inner periphery of the cam barrel, a bending member configured to bend a light flux from an object from the first optical axis towards a second optical axis, and a guiding member extending in a direction parallel with the second optical axis and configured to support and hold the bending member to be movable back and forth in the direction parallel with the second optical axis, wherein the guiding member is configured to enter into a notch, which is provided to the cam barrel, when the optical member is stored into a space along the first optical axis into which the bending member has retracted.