To provide an imaging device and a control method of the same which allows imaging of a high-image-quality moving image with reduced variation in exposure when an exposure condition is varied with variation in brightness of a subject.

On the basis of the luminance value acquired before the start of photographing the moving image, a predetermined charge accumulation time, and a predetermined photographing sensitivity, a diaphragm value at the time of start of photographing the moving image is set. When the luminance value varies during photographing of the moving image, exposure control is performed such that the charge accumulation time and the photographing sensitivity are changed preferentially to the diaphragm value.