PURPOSE: To obtain a low-price image sensor with superior characteristics, by using amorphous silicon, which contains deped boron as a photoconductive element, for an image sensor which utilizes resistance variation of the photoconductive element.

CONSTITUTION: A photoconductive element layer 23 uses amorphous silicon which contains boron doped at a 1×10-4∼5×10-7 mixing mol ratio of monosilane to diborane, and the gap between the layer 23 and an adjacent electrode 24 is set to ≥10μm. Consequently, superior spectral sensitivity characteristics are obtained, various light sources are usable, and the generation of a leakage current is prevented to prevent a character from blurring and an image from fogging.