An image sensor includes a transfer gate including a gate buried portion extending into a semiconductor substrate from a surface of the semiconductor substrate, a plurality of photoelectric conversion parts that are disposed in the semiconductor substrate on a side of the gate buried portion and vertically overlap each other, and a plurality of floating diffusion parts that are apart from and vertically overlap each other in the semiconductor substrate on other side of the gate buried portion, wherein at least one of the floating diffusion parts is positioned at a height of at least one of corresponding photoelectric conversion parts.