In a multimedia contents converting apparatus configured to convert input multimedia contents to be displayed with a predetermined size, including text media and the other media, into output multimedia contents to be displayed with a size smaller than the predetermined size, a spatiotemporal layout information setting processing unit sets a display time of the text media included in layout information on the basis of a display time of the text media calculated in a text display time calculation processing unit, and sets a playing time of the other media included in the layout information on the basis of the display time of the text media set as the layout information.