PURPOSE: To clearly mark the identifying mark, etc., by changing the surging pressure by controlling the responsiveness of the pressure controlling valve with the responsiveness adjusting means, and applying pressurization instantly by utilizing this surging pressure positively.

CONSTITUTION: The hydraulic pressure to be introduced in the hydraulic cylinder 4 is controlled with the pressure controlling valve 11, and the prescribed marking is executed by pressing the marking punch to the product to be worked with the pressurizing motion of this hydraulic cylinder. The pressure controlling valve 11 has the pilot-poppet valve 34 and provides the pilot-valve 16 which lets the 2nd side pressure escape from the drain port with opening the poppet valve 34 if the 2nd pressure is over the set-pressure with using the 2nd pressure as the pilot pressure. The main valve 23 of normal open type having the main valve piston to open / close the flowing path connecting the 1st side path and the 2nd side path applied with the energizing force to the opening direction with the main valve spring 25, and closing the above flowing path following to cracking of the pilot valve is provided. On the main valve, the means for controlling the responsiveness changeably by adjusting the spring force of the main valve spring is provided. Therefore, instantly pressurizing the punch with the surging pressure can be realized.