Method of manufacturing laminated core

A method of manufacturing a laminated core comprising:

• supplying a workpiece plate to a die;
• obtaining a rectangular processed body by punching the workpiece plate using the die;
• and
• obtaining a laminated core by laminating and fastening a plurality of processed bodies,
• wherein obtaining the rectangular processed body includes:
• a slit forming step of forming a slit outside a processed body forming area in the workpiece plate along a long side of the processed body forming area, wherein the processed body forming area corresponds to an area formed as the processed body;
• an inner diameter removal step of punching a center portion of the processed body forming area in a circular shape;
• and
• a processed body removal step of punching the processed body forming area after the slit forming step and the inner diameter removal step, and
• wherein in the inner diameter removal step, the center portion is punched while a reinforcement member is inserted into the slit, and
• wherein in the inner diameter removal step, the center portion is punched in a state where the workpiece plate is fastened by inserting a pin into each pilot hole of a plurality of pilot holes which surround the processed body forming area, while the reinforcement member is inserted into the slit.