An image capturing apparatus which a lens unit is interchangeable, comprises an image capturing unit which captures images using an image sensor, an synthesizing unit which synthesizes a plurality of images, and a controlling unit which controls predetermined synthesis processing for creating a synthetic image by causing the synthesizing unit to synthesize a plurality of images that have been obtained by the image capturing unit performing image capturing a plurality of times, wherein, if it is judged that a lens unit that has been replaced after a first image for the synthesis processing was acquired is a lens unit having an image circle that is different from that of a lens unit that was mounted before the replacement, the controlling unit controls the image capturing unit to not capture a new image for creating the synthetic image.