There are provided core part manufacturing method and apparatus for manufacturing a core part of a rotary electric machine. The core part manufacturing method includes: injecting a molten resin from a side on one end surface of an iron core body into a plurality of space portions provided in the iron core body in a state where the iron core body is sandwiched and pressed. In injecting of the resin, a contact surface on an opposite side to a side where the resin is injected includes: a relief portion that is recessed without contacting to the one end surface; and a remaining portion that is adjacent to a non-contact region. The remaining portion is disposed in the contact surface on an outer peripheral side from the non-contact region, and the relief portion is disposed further in the contact surface on an outer peripheral side from the remaining portion.