An imaging apparatus capable of increasing the accuracy of detection of an outside flash of light.The imaging apparatus includes an imaging unit that sequentially captures images using a CMOS-type image sensor, and a flash determination unit that determines the presence/absence of a flash based on the images captured by the imaging unit. The flash determination unit monitors an amount of change in the average luminance level of a predetermined region in the lower area of the screen in the images captured by the imaging unit, and determines the presence/absence of a flash based on the amount of change in the average luminance level.