A particle detector according to one embodiment includes: superconductive lines, conductive lines, insulating films, a first detection circuit, and a second detection circuit. The superconductive lines extend in a first direction and are arranged in a second direction intersecting the first direction. The conductive lines extend in a third direction different from the first direction and are arranged in a fourth direction intersecting the third direction. The insulating films are each interposed at an intersection point between one of the superconductive lines and one of the conductive lines. The first detection circuit detects a voltage change occurring in the superconductive lines. The second detection circuit detects a current or a voltage generated in the conductive lines when the voltage change occurs.