The present invention provides a deburring device for a punch press which can remove burrs produced along a slot or a cut portion formed in a plate material by punching or cutting using a punch press so that the removal is carried out as a process with the same punch press. A deburring device 6 for a punch press has an upper tool 7 and a lower tool 8 arranged opposite each other. The upper and lower tools 7, 8 each have a ball holding member 22, 32, respectively, and a ball 23, 33, respectively, rotatably supported by the ball holding member and projecting from a surface of the ball holding member 22, 32 toward an opposite surface of the opposite ball holding member 32, 22. Each of the upper and lower balls 23, 33 has a diameter larger than the width of the slot A, in its portion projecting from the ball holding member 22, 32, respectively, the slot A being formed in the plate material W so as to extend across the plane. The plate material W moves with the vertical pair of balls 23, 33 partly fitted into the slot A and with the plate material W sandwiched between the upper and lower balls 23, 33 to continuously remove burrs (a) produced along a longitudinal direction of the slot A. The deburring device 6 continuously removes not only the burrs produced along the slot A but also those produced along a cut portion in the plate material W as described above.