The present invention discloses a server for transmitting and receiving messages for a signaling (S) layer in MMT (Moving Picture Experts Group Media Transport), which includes a first sub-layer of the S layer for producing first messages to provide information necessary for the use of MPEG, a second sub-layer of the S layer for producing second messages to provide information used for delivering MPEG media, and a delivery (D) layer for making external and internal deliveries of the first and the second messages, wherein each of the first and the second messages includes at least one field corresponding to each of the message type, version, length, extension field and payload.