A die machine for manufacturing a laminated iron core includes a first working row for punching out iron core pieces from a steel sheet material and a second working row for punching out electrically insulating sheet pieces from an electrically insulating synthetic resin sheet material. Each iron core piece includes a spindle hole and a plurality of slot holes for receiving coil windings. Each electrically insulating sheet includes a spindle hole and a plurality of slot holes which have a substantially similar configuration to, but are smaller than, the slot holes of the iron core pieces. The die machine includes a stacking die mold for selectively receiving the iron core pieces and the electrically insulating sheet pieces such that successive stacks of iron core pieces are sandwiched between electrically insulating sheet pieces.