To realize a more effective display in chatting by utilizing the three- dimensional display function of a shared virtual space effectively.

When a user B (or C) participating in the shared virtual space detects a prescribed specific command existing in a text in the case of receiving the text transmitted from a user A, the browser generates a character string object 702 obtained by making a text character string ('Hellow') added with the command three-dimensional and displays this object 702 before the avatar 701 of the user A within the shared virtual space of the user B (or C). In the case of voice chatting, after recognizing received voice and converting it into a text, the presence or absence of the specific command within the text is judged to decide the propriety of making the text three-dimensional.