To provide a sheet boring device capable of maintaining the accuracy of a high moving distance of a moving member and the high durability of a drive means.

In a press punch system, a punch motor 221 is started after stopping a conveying motor 208 and a boring operation is performed. A sheet post processing device control part 501 calculates an over-run amount when a slider 260 is stopped by an initial operation. The sheet post processing device control part 501 starts the punch motor 221 at a time ΔT0 corresponding to the over-run amount before timing for stopping the conveying motor 208. When a punch home position 2 sensor 272 and a punch home position 1 sensor 271 are turned on after the starting, the sheet post processing device control part 501 stops the punch motor 221.