To provide a contents server device which can improve user's convenience of sending and receiving data through a computer network and the communication speed needed to send and receive the data.

This device has a means which receives contents sent from a contents company side and based upon a contents purchase request from a user-side terminal and stores them in a storage means, a data confirming means which confirms an error of data with the contents company side terminal having sent the sent data, a contents reception notice issuing means which issues the reception notice of the contents to the user side terminal having made the contents purchase request, and a means which sends the contents stored in the storage means to the user side terminal having made the contents purchase request at a downloading request from the user side terminal having made the contents purchase request.