Provided is a method for manufacturing a gasket-constituting plate made of metal, in which a folded-back part whose thickness is set to be less than the thickness of a general part is provided at a periphery of a combustion chamber hole. The method includes, with a raw metal plate being held between a blank holder and a drawing die having an extrusion hole, extruding the raw metal plate in a thickness direction thereof by using a drawing punch as an extrusion tool to form a projecting part in the raw metal plate, and causing a tensile force to act on the raw metal plate due to the extrusion so as to elongate the raw metal plate, to form a thin peripheral wall part at an outer peripheral portion of the projecting part.