PURPOSE: To enable automatic setting of injection conditions by a method wherein storing time from the injection to the reaching of the max. injection pressure and optimum values of parameter of injection conditions corresponding to the injection during the period into a memory to perform a trial injection.
CONSTITUTION: A memory M memorizes the time from the injection to the reaching of the max. injection pressure and optimum values of parameters of injection conditions corresponding to the amount of injection during the period. A control means CM detects the time and the amount of injection until the max. injection pressure is detected by an injection pressure detection means PS employing an injection time detection means TS and an amount of injection detection means MS and parameter values of injection conditions are read out of the memory M from the time and the amount of injection detected to be set on an injection conditions setting means SM. Thus, when a new die is used, after an trial injection is done once, the time to the maximization of the injection pressure and the amount of injection done during the period as obtained by the trial injection are used to automatically determine and set parameter values optimum injection conditions from a table stored in the memory. Thus, the optimum injection conditions can be determined by one trial injection.