The digital comic editor edits a piece of master data of a digital comic suitably for efficiently viewing a digital comic which has an image size larger than a screen size of a predetermined mobile terminal. The digital comic editor enables the master data of the digital comic to be appropriately edited. The master data includes a piece of image file having high resolution image of the entire page of the comic and an information file having described therein a piece of frame information including a piece of frame region information of the frame within the page. Particularly, the digital comic editor displays a frame boundary while superimposing the frame boundary on the image based on the frame region information included in the information file and displays a border F corresponding to the screen size of the predetermined mobile terminal on the image. The digital comic editor allows an editor to virtually drag and shift the position of the displayed frame boundary while referring to the border F; thereby the frame region information can be corrected to match with the screen size of the mobile terminal.