A work subject material comprising a metal plate for use in punching and/or bending and, attached thereto, a surface protection sheet, characterized in that the surface protection sheet comprises a support base material and an adhesive layer superimposed on one surface of the support base material and that the surface protection sheet exhibits a coefficient (I) not more than 21.0, a coefficient (II) not less than 4.0 and a coefficient (III) not more than 1.5, which are calculated by the following formulae: (I) thickness of support base material (mm)×elongation at break of surface protection sheet (%); (II)=thickness of support base material (mm)×strength at break of surface protection sheet (N/20 mm); and (III)=coefficient (I)/coefficient (II).