A processing method for a substrate having a metal exposed and having cutting lines of a predetermined width set thereon includes: a structural body disposing step of disposing two structural bodies on the metal along respective edges in regard of the width direction of the cutting line, with a gap corresponding to the width therebetween; and a cutting step of causing a cutting blade to cut into the substrate from between the two structural bodies to cut the substrate along the cutting lines, after the structural body disposing step is carried out.