PURPOSE: To favorably execute die casting forming to a material having difficult-to-work by passing a metallic material to be worked through runner in a die for die casting under solidliquid coexisting condition and injecting this into inner cavity in the die for die casting.

CONSTITUTION: The solid-state metallic raw material 9 to be worked discharged at the fixed quantity is charged into between front face induction coil 7 in induction coil 7 for heating and a plunger tip 10. Then, the raw material 8 is inserted into the induction coil 7 by advancing the plunger tip 10 and heated into the solid-liquid coexisting range at this position. When the raw material 8 during heating reaches the prescribed solid phase, this raw material 8 is injected into the die for die casting with the plunger tip 10 to execute the forming. This solid phase ratio may be prediced by measuring temp. of the raw material 8 during heating or by setting the time after beforehand separately obtaining relation between output and time of the heating device and solid phase ratio.