The power consumption is reduced in an imaging apparatus that detects the presence or absence of an event. In a pixel array unit, a plurality of transfer transistors that transfer charges from mutually different photoelectric conversion devices to a floating diffusion layer is provided. A scan circuit simultaneously controls the plurality of transfer transistors in a pixel addition mode in which pixel addition is performed, to transfer the charges and sequentially controls the plurality of transfer transistors in a normal mode in which pixel addition is not performed, to transfer the charges. An event detection unit detects the presence or absence of a predetermined event on the basis of an addition signal which is an analog signal generated in the normal mode, and generates a detection result. A mode control unit sets one of the pixel addition mode and the normal mode on the basis of the detection result.