The present invention aims to perform streaming delivery with compensating missing data when a part of the streaming data of the streaming delivery is missing. On receiving a delivery request to a media server from a client, a cache checking unit checks if the streaming data to be delivered is stored in a cache data storing unit. If not stored, the cache checking unit sends the delivery request to the media server, and a streaming data caching unit receives the streaming data delivered from the media server and judges an existence of missing data within the delivered streaming data. If exists, a missing data requesting unit sends a delivery request for the missing data to the media server, and a streaming data delivering unit performs the streaming delivery of the streaming data and the missing data received from the media server to the client.