PURPOSE: To obtain a joining method suitable for mass-production process without any defect at the interface of the joined metals by bringing molten metal into contact with solid phase surface of a metal in the pressurizing condition and cooling.

CONSTITUTION: At first, the molten metal 4 is poured in a metallic mold 1 and successively, the solid metal 2 is inserted into this molten metal to bring into contact with both metals. At the time of bringing the solid metal surface into contact with the molten metal 4, in order to obtain the firm joined surface, it is desirable to use the solid metal in the heating condition. It is desirable to use the metallic mold in the heating condition, too. Depending on the shape of the metal complex body, the solid metal is inserted into the molten metal to bring it into contact with both metals. After bringing it into contact with both metal, the pressurization is executed from the molten metal side or the solid metal side to integrate both. The pressurized integrative metal is taken out from the metallic mold after cooling, and if necessary, by machining, etc., the metal complex body is obtd. By this method, the metal complex body having high reliability without any defect at the interface of the joined metal can be manufactured.