PURPOSE: To eliminate securing process by applying a winding onto a laminated core with tension sufficient for securing them.

CONSTITUTION: Plural sheets of pressed iron plates are laminated and plastic insulators 10 are provided on the opposite end faces in front and rear of the laminated core and on the inside of slot. The laminated core 11 insulated with the insulators 10 is then applied with a winding by means of an automatic winding machine. Accuracy of the laminated core 11 in the laminating and circumferential directions is ensured by the winding machine, and since force for preventing motion of the core is applied in the laminating direction the iron plates are secured tightly sheet by sheet. Further, since tension is applied continuously onto the winding when winding operation is started, the core is secured tightly when winding operation finishes.