An error check apparatus including, a packet protocol error check processing circuit configure to detect a protocol error of a packet, a retry control circuit configured to receive the protocol error of the packet from the packet protocol error check processing circuit, and to perform request for retry for data of the packet if the received protocol error has not been detected from a packet retransmitted by retry request, and an error notification circuit configured to notify of the protocol error of the packet to a processing unit in a higher-level layer if the protocol error is not a first protocol error for the packet.