A manufacturing method of a rotor may be provided with: arranging a magnet and a thermoplastic in a magnet fixing portion of a rotor core including a laminate in which a plurality of metal plates is laminated, the magnet fixing portion including a hole and/or a trench provided in the rotor core and extending along a lamination direction of the laminate; heating the rotor core while rotating the rotor core around a center axis of the rotor core, with the center axis intersecting a vertical direction; and cooling the rotor core to fix the magnet to the rotor core via the thermoplastic while rotating the rotor core around the center axis, with the center axis intersecting the vertical direction.