PURPOSE: To utilize all printers fully by checking the amount of data to be outputted to a requested print out queue in advance and performing the redistribution of the queue so that the amount of output data of the respective printers are nearly equal.

CONSTITUTION: A print data amount calculating means 3 knows a print file name by receiving a message, finds a print file entry from a disk medium, and further calculates the amount of data to be printed out. A message weighting means 4 weights respective messages. A message queue redistributing means 5 queues the respective messages which are distributed according to the weight values of the messages in corresponding message boxes as many as the printer. Consequently, the respective printers 1 can be used effectively.