To provide a die casting system which can obtain a product with a desired special shape by applying pressure to a product directly after the production of a die-cast product and causing plastic deformation.

When the movement of a product grasping arm 7 is completed, a product 400 is grasped in a position facing to dies 5, 6 for plastic working, and, when upper and lower hydraulic cylinders 3 for plastic working are energized to an extruding direction, the dies 5, 6 for plastic working move, and the product 400 is subjected to plastic working. In this state, time has been only passed from 7 to 8 s after the completion of the product 400, high temperature is still retained. Thus, plastic working by the dies 5, 6 for plastic working is sufficiently possible.