A detection device, comprising an image sensor provided with a plurality of pixels having a plurality of light receiving sections corresponding to a micro lens, capable of adding output signals of the plurality of light receiving sections in accordance with phase difference detection direction and outputting an added signal, and a processor for performing focus detection or depth detection using phase difference detection, based on the added signal of the image sensor, whereby the image sensor makes height of a potential barrier between the light receiving sections different in accordance with the plurality of phase difference detection directions, and the processor sets charge storage determination level differently in accordance with the phase difference detection direction, and controls charge storage operation of the image sensor based on the added signal and the charge storage determination level.