In the computer apparatus which has a processing unit, a power consumption measuring unit, and a power counter, the power consumption of running programs on the processing unit is measured at arbitrary constant period, wherein the measuring value is integrated to the power counter. When the power counter overflows, the processing unit is interrupted for sampling information required for analysis. Then the processing unit which received the interruption executes a sampling of the power consumption base. So, power consumption based sampling and profiling becomes to be enabled.