A data editing apparatus has: a storage unit which stores first and second project data; a temporary screen data creating unit which creates temporary screen data based on screen data selected from among a first group of screen data; a temporary label list creating unit which creates a temporary label list including a label written in the temporary screen data; a temporary data changing unit which replaces the label written in the temporary screen data and the temporary label list with a label which does not overlap with the label written in a second label list, when the label written in the temporary screen data and the temporary label list is written in the second label list; and a project data adding unit which adds allocation information written in the changed temporary screen data and temporary label list to the second label list.