To provide a method for supplying a computer program with which a scrupulous additional function, etc., of the computer program can be supplied from a seller to a consumer while being freely and also safely to the consumer and accompanying reliable charging in regard to the seller.

A server 102 and a terminal 103 which are connected via a network 101 are provided, and the server 102 is provided with a means for receiving a request for the computer program via the network 101, a means for receiving the serial number of the computer program via the network, a means for receiving personal identification number via the network, a means for inserting the serial number and the personal identification information into the computer program and a means for transmitting the computer program with the serial number and the personal identification information inserted thereinto the terminal 103 via the network. The serial number is written on a book to be sold.