SHUTOFF DEVICE

An object of the present invention is to provide a shutoff device capable of suppressing reduction in detection precision of a DC power supply. A magnetic core (10) is electromagnetically coupled to two conductors (90) that allow an AC current to flow through. An exciter (30) is configured to supply a winding (20) with an excitation current that is an alternating current. A current detector (40) is configured to detect a current flowing through the winding (20). A DC component detector (50) is configured to detect a DC component level from the current detected with the current detector (40). Two contact elements (70) are respectively disposed along the two conductors (90). A discrimination controller (60) is configured to: turn the two contact elements (70) on when the DC component level detected with the DC component detector (50) is less than or equal to a threshold; turn the two contact elements (70) off when the DC component level detected with the DC component detector (50) is greater than the threshold; and turn the two contact elements (70) off in de-energized condition.