There is provided an imaging apparatus having a viewfinder optical system; a first image sensor; a photometric sensor; and optical path changing means. The viewfinder optical system has a first reflective surface that reflects a monitoring luminous flux, and the first reflective surface changes a reflection angle of the monitoring luminous flux. A change in a reflection angle of the first reflective surface causes a course of the monitoring luminous flux to be switched between a first optical path and a second optical path. In a case of second optical path, a travel direction is changed with the optical path changing means placed on the second optical path, causing a photometric processing to be performed using the first image sensor, while in a case of the first optical path, the photometric processing is performed using the photometric sensor.