To provide a mold in which a connection key and a key hole to be fitted on the connection surface of a split type mold can be repaired easily with a repairing period curtailed and repairing costs reduced.

In a mold which is integrated by a process in which a connection key fitted on the connection surface 11a of one mold core 11 is inserted into a key hole formed in the connection surface 12a of the other mold core 12 to connect a pair of mold cores 11, 12 together, the connection key is formed with round rod-shaped pins 14a, 14b fitted to the mold cores, and bushes 17a, 17b into which the pins 14a, 14b are inserted are fitted to the key hole.