video file and a block management table for managing the recording state of the storage medium are recorded in advance the video server 52 updates these tables in accordance with an instruction from the gateway server 51 the gateway server 51 is provided with a processing unit 511 and a memory 512 the processing unit 511 is embodied as a controller for controlling the memory 512 and the video server 52 and is configured by a microprocessor such as a cpu or the like as the memory 512 for example a ram is used when the removable storage medium 20 is connected to the reading unit 11 the processing unit 511 updates the file management table and the block management table recorded in advance on each of the memory 512 and video server 52 prepares to transfer a video file recorded on the removable storage medium 20 to the video server 52 and prepares to carry out non linear editing of the video file by using the non linear editing unit 30 if the preparation for transfer of the video file recorded on the removable storage medium 20 is completed the processing unit 511 transfers the video file to the video server 52 and updates the file management tables and block management tables of the memory 512 and video server 52 if the processing unit 511 receives a request to read the video file from the non linear editing unit 30 the unit 123 outputs the requested video.