When downloading a Java.TM. application AP from a server 40, a scheme and a transmission port number used by server 40 when downloading Java.TM. application AP are stored in addition to a host name of server 40. Then, when the Java.TM. application AP accesses a resource on the Internet, the host name of a resource to be accessed, and a scheme and a destination port number are compared with the stored host name, scheme, and transmission port number. The network access is permitted only when the compared items agree with each other.