PURPOSE: To easily count the instruction executing frequency by calculating the executing time of each program based on the number of instructions for each type and the information corresponding to the instruction executing time and editing and outputting the counting result.

CONSTITUTION: When a counting action is through with the instruction executing frequency, and a command is inputted from an input device 1 for release of a branch instruction interruption mode of a preference level number. This fact is informed to a control part 21 via an input information analyzing part 20. Thus the branch instruction interruption mode is released and the working of a branch instruction interrupting mechanism 30 is stopped. At the same time, a command is given to a counting result to the preference level number. The part 23 calculates the executing time of each program to be measured based on an instruction executing time corresponding table 8 and via an instruction executing frequency memory part 6 and delivers the counting result to an output device 7.