Abstract: A disk rotor is produced using pre-forms. A manufacturing device 10 includes lower mold 11 and upper mold 12. The lower mold 11 includes support block 13, main body part of the lower mold 14, inclined pins 15, core elements 16 and slider 17. In securing and supporting pre-forms 4A, 5A, a cylinder 18 is actuated to cause upward movement of the support block 13 and the main body part of the lower mold 14, during which movement, core elements 16 and slider 17 are slid relatively outwards along inclined pins 15. In this state, the pre-forms 4A, 5A are guided to preset sites. The support block 13 and the main body part of the lower mold 14 are then moved downwards, during which movement, core elements 16 and slider 17 are slid relatively inwards along the inclined pins 15. In this state, the pre-forms 4A, 5A are supported and secured stably to define a cavity.