Provided are a method and a device for descaling that make it possible to effectively remove oxide scale from the surface of a metal wire. The descaling includes spraying the surface of a metal wire (W) with a mixture (9) of water and hard particles from a plurality of nozzles (8). The plurality of nozzles (8) include a plurality of self-cleaning nozzles that spray at a spray angle () of 90 or smaller with respect to the metal wire (W). The spray angle () is the angle formed by the central axis (X) of the spraying and a vector (Vt) indicating a conveyance direction that originates at the intersection (P) of the central axis (X) and the metal wire surface.