An image capturing apparatus includes: an image capturing element in which a plurality of pixels and phase difference pixels are formed within an effective pixel region; a photographing lens; a phase difference amount detecting unit analyzing a captured image signal and obtaining a phase difference amount from detection signals of two of the phase difference pixels that make a pair; and a control unit obtaining a defocus amount of a photographic subject image from the detected phase difference amount and performing a focusing control, in which the control unit obtains a parameter value regarding a ratio of the defocus amount and the phase difference amount based on photographing lens information of the photographing lens and a light receiving sensitivity distribution indicating sensitivity for each incident angle of incident light for the two of the phase difference pixels that make the pair, and obtains the defocus amount.