A Controller Area Network (CAN) node includes a conversion and retransmission unit which retransmits a transmit message if the transmit message carries a retransmission ID out of ID codes, by changing the ID code of the transmit message to a retransmission-specific ID corresponding to the retransmission ID, where the ID codes indicate priorities of transmit messages, the retransmission ID indicates that the transmit message is to be retransmitted, and the retransmission-specific ID is an ID code specifically for use in retransmission, and a conversion and reception unit which checks whether an original message corresponding to a retransmit message has been received successfully, the retransmit message being a receive message carrying the retransmission-specific ID, and discards the retransmit message if the original message corresponding to the retransmit message has been received successfully, but converts the ID code of the retransmit message into a retransmission ID corresponding to the retransmission-specific ID if the original message corresponding to the retransmit message has not been received successfully.