An electronic camera capable of both still picture photographing and motion picture photographing in which one operation can be switched over to the other with ease and in which a bright image of the object is provided in the viewfinder with little attenuation in the video signal level. Upon selection of the motion picture photographing mode, the image reflecting mirror is automatically retracted from the photographing optical path and the focal plane shutter is maintained open. The image reflecting mirror drive mechanism and the focal plane shutter drive mechanism are used for both still picture photographing and motion picture photographing operations. Also, the shutter release switch is used for both operations. In the motion picture photographing mode, the degree of opening of the aperture opening and closing mechanism is changed in accordance with the luminance of the image being photographed, while for still picture photographing, the exposure is controlled with the focal plane shutter.