Disclosed is a message processing unit provided in a PLC system including a master and a plurality of slaves. The message processing unit is provided to each of the slaves and includes a first filter configured to receive a message transmitted from the master and to determine whether the message is a broadcast message, a second filter configured to receive the message delivered from the first filter and to determine whether the message is a message-to-be-processed, and a processor configured to process the message he delivered from the first filter or the second filter.
