Provided are a module division assistance device, a module division assistance method, and a module division assistance program for automatically extracting a divisible module by utilizing information relating to a function used by a module. A keyword obtaining unit of an information processing device collects data relating to a function used by a module into keyword use data organized by modules, and a data analysis unit uses the data and a calculation method for an indivisibility calculation item specified by a user and stored in an indivisibility calculation item list, thereby calculating an indivisibility, and stores the indivisibility into indivisibility data. Then, with respect to a module to be subjected to division determination, a module division determination unit compares the indivisibility relating to a function relevant to the indivisibility calculation item specified by the user with a threshold value stored in the indivisibility calculation item list, thereby determining whether the module can be divided or not.