PURPOSE: To provide a press brake by which engagement and regulation can be performed with high precision between a punch and a die and high precision bending can be carried out.

CONSTITUTION: This hydraulic press brake is provided with a pressure detector to detect the pressure of a hydraulic cylinder when a work is bent by punch 9 and die 15. A controller 23 is provided with an arithmetic part to calculate a theoretical access value D between the punch and die according to the shapes and dimensions of the punch 9 and die 15, the plate thickness T and the bent angle A of the work W, an arithmetic part to calculate a distortion amount of a side plate 5 according to a detection value of the pressure detector and a control part to control a rise stopping position after a lower apron 13 is corrected according to a corrective amount of an upper limit setting valve branched and connected to aa hydraulic circuit of the hydraulic cylinder, the distortional amount and the theoretical access value.