To provide a punch press having a scrap suction device composing a scrap-rise preventing mechanism, which punching press can perfectly operate the scrap-rise preventing mechanism by forcedly removing a scrap stuck when periodically discharging the scrap, and retrying the operation for keeping the vacuum pressure normal to early remove the scrap causing an abnormal negative pressure.

The punch press comprises the scrap suction device composing the scrap-rise preventing mechanism, and a scrap box 14 for sucking and storing the scrap K therein, wherein the scrap box 14 has a lid 9 capable of opening and closing. The punch press further comprises a negative pressure detecting means 4 for detecting the negative pressure in the state that the lid 9 of the scrap box 14 is closed, and a scrap removing means 5 for removing the scrap K by opening and closing the lid 9 when the negative pressure detected by the negative pressure detecting means 4 is abnormal.