In a production apparatus (1), after rear holders (7a, 7b) and a housing body (8) are molded by molding die cavities, slides (11a, 11b) are moved apart from the housing body (8). Then, cylinders (16a, 16b) are driven to move the rear holders (7a, 7b), holders (13a, 13b) and the slides (11a, 11b) together with slide plates (14a, 14b), so that the rear holders (7a, 7b) are located in opposed relation to the housing body (8). Then, cylinders (19a, 19b) are driven to move the rear holders (7a, 7b) toward the housing body (8), thereby provisionally retaining the rear holders (7a, 7b) on the housing body (8). Therefore, the amount of movement of the slides (11a, 11b) is small, and it is not necessary to provide any space for holding the slides (11a, 11b), moved into their respective stand-by positions, and therefore the small-size design of the production apparatus can be achieved, and also the production efficiency can be enhanced.