A loader section (102) for converting a program from a class file to a runtime execution format, a runtime saving section (103) for performing a runtime saving process by which a runtime execution format is converted to a temporary runtime execution format, a temporary runtime execution format storing section (302) for storing a temporary runtime execution format, and a post-loader section (105) for performing a post-loader process by which a temporary runtime execution format is converted to a runtime execution format are included, and determination is made whether or not there is a temporary runtime execution format in the temporary runtime execution format storing section when a start-up of a program is instructed, the loader section is requested to perform conversion to a runtime execution format if there is none, and the post-loader section is requested to perform conversion to a runtime execution format if there is any. As a result, it is possible to reduce a start-up time of a downloaded program in a program distribution service.