PURPOSE: To provide a sheet transport apparatus which can decrease load torque to the time of transporting documents and recording paper sheets.

CONSTITUTION: A one-way clutch 10 on which a cam 11 is integrally formed is disposed on one feed roller 9, and the one-way clutch 10 is locked when the feed roller 9 is rotated in the direction opposite to the direction of transporting sheets A ratched lever 13 is integrally formed on the cam 11 so that even if the feed roller 9 is rotated in the direction of transporting sheets, the cam 11 is not rotated together. Accordingly, when a document 2 or recording paper sheet 6 is transported by the feed roller 9, neither one of a reading unit 5 an a recording unit 8 which is not needed for transport may press the feed roller 9. Thus, the movement of the cam prevents one of the reading unit 5 and the recording unit 8 from being pressed by the feed roller 9, so that unnecessary frictional torque is not generated so as to decrease load torque.