To lower a newly expended cost for a metal mold, and to permit simple reassembling.

In this metal mold system for a compound insulator composed of a core member, and a housing consisting of a barrel part and plural umbrellas around the core member, a metal mold 1 is formed by longitudinally coupling plural pairs of segments 2 having umbrella upper surface forming parts 3 on one main surfaces 2a and umbrella lower surface forming parts 4 on the other main surfaces 2b, such that the main surfaces of the adjacent segments 2 are facing each other. Here, parts 3-1 corresponding to umbrella tip parts 11 of the umbrella upper surface forming parts 3 forms crook portions of the umbrella tip parts 11. And, parts 4-1 corresponding to the umbrella tip parts 11 of the umbrella lower surface forming parts 4 are formed by planes identical with the main planes.