1. A C language-based hard/soft cooperative verifying simulator for performing cooperative verification of hardware and software, comprising: a plurality of time keepers provided every plurality of threads constituting simulation models corresponding to the hardware and software and each provided with a first variable for holding a simulation time, a second variable for holding a summation time, a break request queue for storing break requests, each of which consists of a pair of a break time and a break method, corresponding thereto, and a processing function in order to control a simulation time of each of the threads to which said time keepers correspond respectively; and a C language-based simulator body which advances each managed system time by a given required time in response to a request issued from each of the time keepers and controls context switching between the threads being operated in parallel.