An imaging device including 2-dimensionally arranged pixels for receiving light is provided. The imaging device includes a first area configured to detect a horizontal phase difference based on horizontal phase difference information obtained from pixels configured to detect the horizontal phase difference, a second area configured to detect a vertical phase difference based on vertical phase difference information obtained from pixels configured to detect the vertical phase difference, and a third area configured to detect horizontal and vertical phase differences based on horizontal phase difference information and vertical phase difference information obtained from pixels configured to detect the horizontal and vertical phase differences, wherein the first area is adjacent to a horizontal border of the third area, wherein the second area is adjacent to a vertical border of the third area, and wherein the third area is located at a center of the imaging device.