When first cross-sectional image data representing a target model corresponding to a shape of a three-dimensional printing object, and second cross-sectional image data representing both of the target model and a support model corresponding to a shape of a member assisting the creation of the three-dimensional printing object, are recognized to match each other by at least a predetermined ratio, the second cross-sectional image data is stored on storage means as third cross-sectional image data. By contrast, when the first cross-sectional image data and the second cross-sectional image data are recognized not to match each other by at least the predetermined ratio, synthesis data of the first cross-sectional image data and the second cross-sectional image data is stored on the storage medium as the third cross-sectional image data. The three-dimensional printing object is created based on the third cross-sectional image data.
