A sheet take-out apparatus has a table for loading a plurality of postal matter upright, a backup plate for pressing postal matter in the stacking direction and supplying them to a take-out position, a lower stream side floor belt installed so as to be partially exposed from the table in the neighborhood of the take-out position, an upper stream side floor belt, a take-out roller, and two auxiliary rollers. A difference in the projection position between the auxiliary rollers pressed by the postal matter supplied to the take-out position is detected and the inclination of the postal matter is detected. And, on the basis of the detection results, the moving speeds of the floor belts are controlled so as to correct the posture of the postal matter upright.