To execute automatic switching in an optional priority to a plurality of designated stackers.

This print controller is provided with a means receiving print data from a host system, a means feeding the received print data to a printer in a receipt order, a means for outputting used paper to a plurality of paper output mechanisms, and an operation panel for inputting various information by an operator. A table storing status information about the respective paper output mechanisms and a paper size and priority information to each paper output mechanism inputted from the operation panel is prepared, and by a means recognizing the paper size to be outputted to each paper output mechanism from the information, the paper output mechanism can be automatically switched according to the paper information inputted from the operation panel when no paper output mechanism to be used for printing is designated by the host system.