An interchangeable lens assembly includes a plurality of lens-side claw portions configured to enable engagement with a plurality of camera-side claw portions, and a lock pin concave portion in which a lock pin is inserted. Furthermore, θ1 is an angle formed by a line passing through a fifth lens-side end and an optical axis, and a line passing through a center of a lock pin concave portion and the optical axis, and θ2 is an angle formed by a line passing through a fourth lens-side end and the optical axis, and a line that passes through the center of the lock pin concave portion and the optical axis. In the above, θ1 and θ2 satisfy a predetermined conditional expression.