an endoscope system is provided that includes a processor connectable to various endoscopes to process signals generated by the endoscope being connected . the processor further includes a database , a data selector and a data register . the database is configured to be registered a plurality of pieces of endoscope data , each of which being related to different one of the endoscopes connectable to the connector . each piece of the endoscope data includes priority information indicating the priority of deleting the piece of endoscope data . the data selector selects one piece of the endoscope data based on the priority information . the data register registers a new endoscope with the database by replacing the selected piece of endoscope data with the piece of endoscope data of the new endoscope .