A program editing apparatus includes a user interface control unit, a JSP analysis unit, and a split execution unit. The user interface control unit accepts an input of a split object instruction which specifies a portion to be split off from a JSP file to be processed. The JSP analysis unit determines an accompanying split portion which is split off together with the portion specified by the split object instruction. The split execution unit splits off the portion specified by the split object instruction and the accompanying split portion from the original JSP file. The JSP analysis unit analyzes dependence of variables and objects in the JSP file and splits off a copyable portion by copying. Thus, a program file after split is ensured to operate the same as the program file to be processed.