Disclosed is a claymore mine on which a device for preventing a breakdown attributable to a power noise has been mounted. In order to prevent an electric primer from operating due to a power noise induced by a magnetic field or generated by the falling of a thunderbolt or other factors, such as a communication device, a shield layer formed by weaving or braiding a conductive fiber, such as a carbon fiber, or weaving or braiding a copper-plated tin wire, is formed in the wire and percussion unit of the claymore mine. In order to discharge a power noise introduced into the wire and the percussion unit to the earth, a power noise discharge adaptor including a plurality of diodes, a TVS, a GDT, and an SPD is formed. Accordingly, the introduction of a power noise can be fundamentally blocked, and a power noise can be safely discharged to the earth if the power noise is introduced.