Object collaboration apparatus using message type

In object collaboration via a message, various message types are dealt with. Furthermore, synchronization processing between objects is conducted easily and flexibly. A message type is previously classified and arranged hierarchically. A message/action reaction table 103 arranged on the message type basis is held in a message/action reaction relationship storing part 102. A received message is subjected to matching by a message type classifying/matching part 107. When the received message is matched with a message type dealt with by the message/action reaction relationship storing part 102, the message is given to an action executing part 104. When the received message is not matched with a message type dealt with by the message/action reaction relationship storing part 102, the message is discarded.