supply system 34 only makes up the polishing slurry flowing out from the outer periphery of the polishing pad 32 although the guide wall 36 is bent four times a guide wall may extend straight or spiral the guide wall 36 does not encircle the polishing pad 32 and the polishing slurry partially returns and partially flows out for this reason the polishing slurry supplied to the semiconductor wafer is not deteriorated the polishing apparatus implementing the third embodiment has the combined system 33 however the combined system 33 is replaceable with the wafer holder system 15 and the pad conditioning system 16 if so it is equivalent to the polishing apparatus shown in fig1 and 11 newly equipped with the guide wall 36 the present inventor evaluated the polishing apparatus implementing the third embodiment namely the present inventor plotted the polishing rates in terms of the flow rate of the polishing slurry supplied from the slurry feed nozzle as shown in fig1 plots h is representative of the experimental result that can be achieved when using the prior art polishing apparatus and plots i and j are indicative of the experimental results which can be achieved when using the first and third embodiments respectively when the flow rate was decreased to or below 150 milliliter per minute the polishing rate of the prior.