The sheet material positioning apparatus according to the present invention comprises a pair of left and right side guides (11, 11) mounted so that they may be moved freely and independently with each other in the direction at right angles to the sheet material feeding direction and turned freely independently with each other in a horizontal plane; a pair of left and right front gauges (12, 12) and a pair of left and right rear gauges (13, 13), said front and rear gauges being mounted in the front and rear positions in the sheet material feeding direction so that they may be moved freely and independently with each other in the sheet material feeding direction and also in the vertical direction. Thus, adjusting independently the side guides (11, 11), the front gauges (12, 12) and the rear gauges (13, 13) by moving them individually, centering and positioning of sheet materials of any desired shapes can be achieved.