A manufacturing method of a core for a rotary electric machine includes: forming a crimped portion on both a first magnetic steel sheet and a second magnetic steel sheet. The crimped portion has a recessed portion that is recessed from a first surface and a protruding portion that protrudes from a second surface in a position on the reverse side of the recessed portion on the second surface; and stacking the first magnetic steel sheet and the second magnetic steel sheet while curving the first magnetic steel sheet such that a first surface side bulges out, and inserting the protruding portion of the crimped portion of the second magnetic steel sheet into the recessed portion of the crimped portion of a curved first magnetic steel sheet.