PURPOSE: A subscriber terminal device of an IPTV system is provided to arouse curiosity of a subscriber by replacing object data corresponding to the specific parts of characters in interactive multimedia contents with stored real object data. CONSTITUTION: A subscriber terminal device of an IPTV system comprises the following: a memory part(110) storing real object data on specific parts of characters; a communications part(120) receiving interactive multimedia contents through IP network from a server device(200); and a content reproducing part(130) outputting the interactive multimedia contents through a TV device(300). The content reproducing part replaces the object data to the real object data in the memory part.
