PURPOSE: To provide a superconductive photosensor which is ultrahigh in sensitivity and operates at an ultra-high speed.

CONSTITUTION: A first superconductor layer 12, photoelectric conversion layers 13, 14, and 15, and a superconductor layer 16 are successively laminated on a substrate 11, whereby a laminated type Josephson junction of superconductor layer-photoelectric conversion layer (normal conductor layer)-superconductor layer (SNS-type) is formed of the superconductor layers 12 and 16 and the photoelectric conversion layers 13, 14, and 15. At least, a groove or a hole 17 is provided to the first superconductor layer 12 or the second superconductor layer 16 so as to enable light rays to impinge on the photoelectric conversion layers 13, 14, and 15 from above or below. The photoelectric conversion layers 13, 14, and 15 are formed of photoconductive material or photovoltaic material or P-type semiconductor 13, I-type semiconductor 14, and N-type semiconductor 15 respectively. Furthermore, either of the superconductor layers is formed of barium-potassium-bismuth-oxygen or barium-lead-bismuth-oxygen or niobium element or niobium alloy.