PURPOSE: To protect the right of software stored in a software package and to collect surely the charge of the software by providing a storage medium storing number of permission of the use of an input program.

CONSTITUTION: The number of usage of a program inputted from the software package 3 executed by a central processor 1 is stored in a storage medium 4. When a CPU1 reads the program stored in the package 3 via an input/output device 2, the program supervisory operation is executed. Whether or not the medium 4 is set to a data input/output device 5 is checked at first, and when the medium is set, the number of permission of usage is read from the medium 4. As a result, when the number of permission of usage is deficient, the user purchases newly only the medium 4 sold with a charge and sets it to the device 5 so as to use a program of the package 3. The medium 4 is provided in this way, then the protection of right of the software in the package 3 and sure collection of the charge are attained.