To provide a hardware/software cooperation verifying method capable of executing quick and accurate simulation in the simulation of the whole system in which a software program code and hardware can interact with each other.

The system is provided with plural processor simulation models 103 for simulating software instruction operation, a logical circuit simulation model 105 for simulating a logical circuit part, a model switching means 102 for dynamically switching plural processor simulation models 103, and a synchronizing means 104 for synchronizing the simulation of the processor simulation models 103 with that of the logical circuit simulation model 105.