The aim of this study is to measure the exact average specific cake resistance in cake filtration. Using the new experimental method “filtration-permeation,” the average specific resistances were measured for various conditions as follows. First, the experiment with changing pre-sedimentation time and the filtration of sediment were conducted to determine the influence of sedimentation on the average specific resistance. There was a wide difference between the values of αav with various sedimentation times. Regarding the variation in the pre-sedimentation time, there was maximum 2.9x difference between the measured values of the average specific resistances for the filtration of calcium carbonate suspension. The “filtration-permeation” of bentonite floc and that of biological flow were also performed to establish a method for obtaining the average specific resistance of flocs.