Differential Power Analysis (DPA) aims at revealing secret keys in cryptographic devices by analyzing their power consumption as side-channel information. Although power consumption models based on transition probability were used to evaluate a DPA-resistance in previous studies, the adequacy of this model has not been confirmed enough. In this paper, we show two experiments about information of power consumption precisely, and show that Random Switching Logic which is one of the DPA-countermeasures is in reality not secure against DPA.