An image sensor includes phase difference detection pixels including first group pixels each having a first shield region deviated at one side and second group pixels each having a second shield region deviated at the other side, and image detection pixels arranged in a lattice pattern together with the phase difference detection pixels. The phase difference detection pixels include a first pixel group configured such that an area of the first shield region is equal to that of the second shield region, a second pixel group configured such that the area of the first shield region is equal to or greater than that of the second shield region, and a third pixel group configured such that the area of the first shield region is equal to or less than that of the second shield region.