Abstract: There is provided a manufacturing method of a laminated iron core which is formed of a strip-shaped iron core piece. The strip-shaped iron core piece includes segment iron core pieces connected through a joint positioned in a radial outside, and each of the segment iron core pieces has an artuate shape. The joint by which adjacent segment iron core pieces are connected is folded and lateral ends of the adjacent segment iron core pieces are aligned. The strip-shaped iron core piece is spirally wound while circumferentially shifting mutual joints formed on vertical adjacent layers. Crush processing is performed for flattening a bulged portion in a thickness direction of the segment iron core pieces formed at a time of folding the joint, and the crush processing is performed simultaneously with a time when or after mutual segment iron core pieces arranged vertically are crimped and laminated.