To improve accuracy of bending member by adjusting deflection of ram and running table being pressurized at the lowest limit position of the shaft, in combination of the synchronized operation and independent operations of a plural number of driving shafts, without using any measuring device and the like.

In this press mechanism, the top and the bottom positions of the ram 2 is detected by a linear encorders 14a-14d set in corresponding to the driving shaft positions of each rams. The feed back control to the ram driving servo motors 11a-11d is made possible by inputting the detected value into a NC unit of the control board. When the bending procession is made, the processing information is input in the NC unit in advance to calculate a slow delivery point, a synchronize control stop position and the shaft lowest limit position of each ram driving shafts. Based on the calculated results, all the shafts are synchronized and, the ram 2 is fast descended to the starting position of slow delivery and continuously descended slowly to the synchronize control stop position. Thereafter, each shafts become independent and descend slowly to their lowest limit positions to finish the bending procession.