PURPOSE: To produce belleville springs having resembling characteristics with the same device by drawing a blank of a sheet metal for a spring to a tray shape then thrusting the surfaced drawn to the tray shape on the inside by as much as an adequate extent along the periphery of the tray shape.

CONSTITUTION: A sheet material for a spring of phosphor bronze or the like is first drawn to a semiprocessed good of a belleville spring by means of a die 23 having a recess 22 atop the same and a vertically movable punch 25 having a projecting part 24 conforming to the recess 22 in the same way as in the prior art. A die 33 formed atop with a recess 32 with which the projecting surface of the good 26 makes roughly face contact, a slide cam 34, and a punch 36 which is moved vertically by lateral movement of the cam 34 and has a circular truncated cone-shape head part 35 conforming to the recess 32 are used. The good 26 is placed in the recess 32 of the die 33 and the punch 36 is lowered so that the circular corner 37 in the head part 35 thereof thrusts the circle on the inside by a suitable extend along the peripheral surface of the recessed surface of the good 26. A belleville spring 38 is thus completed.