A license authentication system suitable for use when installing an application in a client PC, comprising: a portable terminal capable of communicating with the client PC by connecting thereto and communicating with a server by connecting thereto via a wireless link, wherein the server comprises temporary right-of-use issuing means for issuing a temporary right of use to the application installed in the client PC, and regular right-of-use issuing means for issuing a regular right of use, wherein the portable terminal comprises means for acquiring the temporary right of use and the regular right of use issued by the server from the server and retaining the same therein, and means for giving the temporary right of use and the regular right of use acquired from the server to the client PC, wherein the client PC comprises license authenticating means for limiting use of each application according to the kind of a right of use, and means for requesting the regular right of use in a state in which the application is being authenticated by the temporary right of use, wherein when each application to be installed in the client PC is acquired, the portable terminal is configured to acquire and retain the temporary right of use issued by the server, and when the client PC installs the application therein, the portable terminal is configured to perform temporary license authentication by the retained temporary right of use to thereby enable use of the application at the client PC, and wherein the portable terminal is further configured to thereafter move to an area capable of communicating with the server and acquire a regular right of use from the server and retains the same therein, and the portable terminal is further configured to perform regular license authentication by the retained regular right of use when a license authentication request based on the regular right of use is made from the client PC. a portable terminal capable of communicating with the client PC by connecting thereto and communicating with a server by connecting thereto via a wireless link, wherein the server comprises temporary right-of-use issuing means for issuing a temporary right of use to the application installed in the client PC, and regular right-of-use issuing means for issuing a regular right of use, wherein the portable terminal comprises means for acquiring the temporary right of use and the regular right of use issued by the server from the server and retaining the same therein, and means for giving the temporary right of use and the regular right of use acquired from the server to the client PC, wherein the client PC comprises license authenticating means for limiting use of each application according to the kind of a right of use, and means for requesting the regular right of use in a state in which the application is being authenticated by the temporary right of use, wherein when each application to be installed in the client PC is acquired, the portable terminal is configured to acquire and retain the temporary right of use issued by the server, and when the client PC installs the application therein, the portable terminal is configured to perform temporary license authentication by the retained temporary right of use to thereby enable use of the application at the client PC, and wherein the portable terminal is further configured to thereafter move to an area capable of communicating with the server and acquire a regular right of use from the server and retains the same therein, and the portable terminal is further configured to perform regular license authentication by the retained regular right of use when a license authentication request based on the regular right of use is made from the client PC.