To provide a die holding technology which can reasonably perform a die holding motion.

In a die-cast device in which dies D1 and D2 after the casting which are carried out from a die cast body are moved in the transverse direction across the carrying-out direction to open the dies, a T-shaped grove 62 is formed in the dies D1 and D2, and a hook 61 is provided on a die opening device 50. When the dies D1 and D2 are carried out from the die cast body, the hook 61 of the die opening device in the waiting mode is inserted in the T-shaped groove 62 of the dies D1 and D2, and the dies D1 and D2 are held in the die-opening direction of the die opening device 50.