An image sensor is provided. The image sensor includes: a pixel array including first and second pixel groups, each of which includes unit pixels arranged in 4×4 array, each of the unit pixels including a photodiode provided, and the first and second pixel groups being alternately disposed in multiple directions; a logic circuit configured to acquire pixel signals from the unit pixels; first microlenses provided on corresponding unit pixels in the first pixel groups; and second microlenses provided on four corresponding unit pixels of the unit pixels included in the second pixel groups. Each of the first and second pixel groups includes a device isolation layer provided between the unit pixels, and a color filter provided on the first surface, and each of the second pixel groups includes an overflow region configured to move electrical charges between adjacent photodiodes.