In a print system, without requiring a standardized command indicating use of a thumbnail image, and without causing an abnormal operation, a print content transmission device directs a print device to use the thumbnail image, wherein print content is described using XML format, and a direction command is described using XML format in the print content. Specifically, in a step S201, a processing control unit (111) proceeds to a step S202 in the case where there is input from a user I/F unit. In the step S202, a unique information addition unit (104) judges whether or not the thumbnail image should be used for printing. In the case where it is judged that the thumbnail image should be used (S202: Yes), the unique information addition unit (104) directs a print content generation unit (108) to add, to the print content, a direction to use the thumbnail image (step S203).