To provide a photographing device which is not restricted more than required at the stage of designing a lens, and also does not need operation to move a mirror for a finder optical system depending on a used lens and also in which the control of automatic focus detection is not cared.

A raising/lowering mirror (semitransmissible mirror) 108 to guide subject light to the finder optical system is moved to an observation position or a withdrawal position in accordance with the initial data (specific information) of the lens 302 stored in the ROM of a lens microcomputer 303, and also the automatic focus detection based on a signal obtained by transmitted light from the raising/lowering mirror 108 and that based on a video signal obtained by an imaging device 101 are switched.