In a sheet processing apparatus which checks sheets and sorts the sheets for a plurality of cassettes on the basis of the check result and conditions for the sheets which are assigned to the respective cassettes, conditions for sheets such as bill types and bill states which are assigned to the respective cassettes are displayed on a display unit. When an instruction to save these setting contents is issued while a cassette and conditions for sheets which are displayed on the display unit are selected, the selected conditions for sheets are assigned to the selected cassette.