Abstract: The present invention is directed to an environment in which a safe program having high thread isolation can easily be constructed, and the effective utilization of resources can be achieved when concurrently processing a plurality of client requests. More specifically, a client request 101 is transformed into a common format, and stored in a queue 125 in the form of packet information. A control unit 127 reads the packet information, and instructs a thread control unit 131 to create a thread. A thread object 141 referenced only from the created thread is created by copying a thread object template 149 prestored in the system. Client requests are divided into three types: creation of an object, utilization of an object method, and deletion of an object, and a thread is created only during the execution of a client request.