An electric comic book delivering server delivers translated electric comic book by transmitting original electric comic book data, mask data and translation data to a client terminal via a communication network. The mask data is used to mask a display portion of first language. The translation data is used to superimpose a display portion of second language on the masked display portion of first language. When the electric comic book delivering server obtains mask data and translation data from another client terminal in which the mask data and the translation data have been created, the electric comic book delivering server registers the mask data and the translation data into a database thereof.