In a sensor chip for forming the light receiving elements of a photo-detection sensor, p-type regions of the photodiodes are formed in a surface portion of an n-type epitaxial layer, and they are respectively contacted with electrodes. A deep n+-region is formed in the part of the n-type epitaxial layer between the adjacent p-type regions so as to reach a buried n+-region. Carriers created with the projection of light in the photodiodes are trapped by the deep n+-region (30). An aluminum film serving as a light shielding film is arranged over the part of a silicon substrate between the regions for forming the photodiodes. Thus, the photodiodes can be operated independently from each other.