Conductive powders are widely used as electrode materials in energy storage devices. Thus, electrical properties of conductive powders are important for applying them in high-performance energy storage devices. In this study, we measured the electrical conductivity of conducive powders as increasing a compression force on the powders. we fabricated a compression tester having a function for simultaneous measurement of electrical conductivity of conductive powders. To eliminate the contact resistance in the measurement, four-point probe measurements were used in the study. We observed the change of electrical conductivities of various conductive powders as function of the applied pressure.