The controller that controls the industrial machine comprises a storage area that stores an operation program, a cache memory, a cache control unit, and an analysis unit, the analysis unit pre-reads a command subsequent to a command included in the operation program loaded in the cache memory, in a case where it is determined that an operation load on a CPU in a command included in the operation program is below a prescribed value, adds, to the command, a cache control command for loading of a subprogram into the cache memory in accordance with a predetermined condition, in a case where a subprogram call command is confirmed present, and makes a cache control request to the cache control unit, responsive to the added cache control command, and the cache control unit loads the subprogram in the cache memory, based on the cache control request.