There is provided an image sensor having a plurality of pixels, each pixel including a light receiving portion configured to receive incident light, a waveguide configured to guide the incident light from a light incident surface to the light receiving portion, and a light shielding portion disposed between the light incident surface and the light receiving portion, for blocking the incident light. The light shielding portion has an opening formed near a light emitting surface of the waveguide. The light receiving portion receives the incident light passing through the waveguide and the opening. A width of a core of the waveguide and a width of the opening are set so that the widths increase as a wavelength of the light incident on a pixel becomes longer.