The invention is directed to a method for caulking a caulking member such as a caulking nut or a caulking bolt to a metal plate. The metal plate is arranged on a die having a caulking protrusion formed on an end surface thereof, the caulking member is arranged on the metal plate while a position of a caulking recess portion of the caulking member is aligned with the caulking protrusion, and a punch is brought closer to the die so that the caulking member is pressed against the metal plate. While an upper surface of the metal plate in a position opposite to the caulking recess portion is restricted by a downward protruding portion of the punch or by the caulking member, the metal plate is plastically fluidized into the caulking recess portion, so that the caulking member is caulked without boring a hole in the metal plate.