PURPOSE: To enable debugging from a specification at the time of execution concerning the program development supporting system for generating an execution form program by preparing the specification.

CONSTITUTION: In the case of preparing a source file 6 from a specification file 4 on a host, the correspondence information of the specification and the generation source is prepared and stored in a correspondence information file 7 by a source generation processing means 5. A line number information preparation processing means 12 compresses the information from the correspondence information file 7 and prepares a line number information file 13 on the host. A line number information transfer processing means 14 transfers line number information to a line number information file 15 on a terminal. A line number information display processing means 6 displays a generated line number from the specification corresponding to a specification file 2 on the terminal and the line number information file 15 on the terminal.