PURPOSE: To simplify the constitution of a core holding frame unit and driving mechanism for holding the unit and to easily execute the maintenance, etc., by arranging an end plate and the base plate so as to be freely approached/ left and arranging a movable restraining claw so as to be advanced/retreated while linking in the interval of approaching/ leaving between the end plate and the base plate.

CONSTITUTION: The link mechanism is worked accompanied with the leaving of the base plate 10 from the end plate 4, and the L-shaped link 15 is shaken to push out the movable restraining claw 12 to an engaging position. The movable restraining claw 12 is engaged with a part to be engaged of the centrifugal casting metallic mold by projecting in the radial direction of the base plate 10. Further, the inside surface of the part to be engaged receives the engaging force of the large coil spring 56 to catch the movable restraining claw 12 shifted in the axial direction of the centrifugal casting metallic mold. Thereafter, a locking claw 76 is retreated by driving a cylinder 75 for locking to release the locking to a flange 66. The driving mechanism 54 for holding the unit is left from the core holding frame unit 53 with a driving block to pull off a main rod 67 from a body sleeve 64.