1. A print processor which prints a document in response to a job request received through a network, said print processor comprising: job accepting means for accepting the job request; queuing means for storing the accepted jobs in sequential order; output means for printing a document specified by the job stored in said queuing means; converting means for converting the document into a format which said output means can interpret; and conversion control means for causing said converting means to convert a document which needs to be converted when being printed by said output means, wherein said converting means informs said conversion control means that it can carry out conversion when conversion processing becomes available, and further wherein said conversion control means sequentially searches the queuing means for the document in a format which said output means cannot interpret from among the documents specified by the job stored in said queuing means, and causes said converting means to convert the format of the document prior to the output means removing the document from the queue and printing the document.