An information processing device comprising: content storing means for storing a content; communication means for receiving, from a preceding device or a request source, and transmitting a request message that includes information indicating the request source that requests the content, a request condition that is a condition for determining the content that is a target of request, and a request-source-stored-content that includes information of a content stored by the request source; request determination means for determining a content that satisfies the request conditions and is not included in the request-source-stored-content in the contents stored in the content storing means ; and request message processing means for, when the content is determined to satisfy the request conditions and determined to be not included in the request-source-stored-content of the request source, updating the request-source-stored-content in the request message by adding information relating to the determined content to the-request-source-stored-content; wherein when the content is determined to satisfy the request conditions and determined to be not included in the request-source-stored-content of the request source, the request determination means is configured to transmit the determined content to the request source via the communication means , and to transmit the updated request message to a next device via the communication means ; and wherein when the content is determined not to satisfy the request conditions, or is determined to be included in the request-source-stored-content of the request source, the request determination means is configured to transmit the request message via the communication means, without update of the request-source-stored content in the request message, to a next device. content storing means for storing a content; communication means for receiving, from a preceding device or a request source, and transmitting a request message that includes information indicating the request source that requests the content, a request condition that is a condition for determining the content that is a target of request, and a request-source-stored-content that includes information of a content stored by the request source; request determination means for determining a content that satisfies the request conditions and is not included in the request-source-stored-content in the contents stored in the content storing means ; and request message processing means for, when the content is determined to satisfy the request conditions and determined to be not included in the request-source-stored-content of the request source, updating the request-source-stored-content in the request message by adding information relating to the determined content to the-request-source-stored-content; wherein when the content is determined to satisfy the request conditions and determined to be not included in the request-source-stored-content of the request source, the request determination means is configured to transmit the determined content to the request source via the communication means , and to transmit the updated request message to a next device via the communication means ; and wherein when the content is determined not to satisfy the request conditions, or is determined to be included in the request-source-stored-content of the request source, the request determination means is configured to transmit the request message via the communication means, without update of the request-source-stored content in the request message, to a next device. <EOS>