PURPOSE: To control the flow of the inside by providing control means of changing the static pressure generated in each position of static pressure generating means constituting static pressure chambers in fluid static pressure pads provided with static pressure chambers.

CONSTITUTION: The static pressure pad is constituted of static pressure pad parts A forming fluid injection nozzles 1, a traveling strip B opposing to the pad parts A, outside boxes 2 enclosing the back part of the nozzles 1, partition plates 3 segmenting the outside boxes longitudinally to plural small chambers, a fluid supply main pipe 4 supplying fluid to the static pressure pad, branch pipes 5 branched from the main pipe 4 and connected to the respective small chambers of the outside box 2, and pressure regulating valves 6 provided to the respective branch pipes 5. Here, if the small chambers at the back of the nozzles 1 are set at required pressures by regulating the valves 6, the static pressure to be generated in the respective positions of the nozzles are controlled. Hence, the flow of the inside is controlled as well.