Manufacturing method for helical core for rotating electrical machine and manufacturing device for helical core for rotating electrical machine

This manufacturing method for the helical core for the rotating electrical machine is provided with: a first step for forming, in a belt-shaped metal plate extending in one direction, a yoke part extending along the one direction and a plurality of tooth parts protruding in the width direction of the yoke part from one side edge in the width direction thereof; a second step for forming a notch at a position between the tooth parts of the yoke part after the first step; and a third step for processing the belt-shaped metal plate into a helical shape by applying bending thereto such that the belt-shaped metal plate is curved in the width direction sequentially from a portion in which the notch has been formed after the second step, and in the third step, the distance between the position at which the application of bending is started and the position at which the notch is formed is limited to a predetermined length or less.