To provide a rotor core of a rotary electric machine with improved yield of material.

A stress circle r necessary in terms of strength is calculated on the basis of a stress exerted from a pin in a circumference of a fixing hole 19 configured to insert the pin therethrough. An inner diameter side c of both end parts in a circumferential direction of a core plate piece 13 is cut so as not to reach the stress circle r. A permanent magnet is buried in the core plate piece 13. A radius line B necessary in terms of a magnetic circuit is calculated in order to enhance a line of magnetic force of the permanent magnet. The inner diameter side c of both end parts in the circumferential direction of the core plate piece 13 is cut on a tangent line s of the stress circle r that intersects P on the radius line B and an end surface f of the core plate piece 13.