PURPOSE: To automatically count the number of executed instructions and, at the same time, to reduce the counting time by dividing a program into blocks at the time of compilation and counting the number of the executed instructions by generating interruptions at every block.

CONSTITUTION: At the time of compilation, a blocking section 11 divides a program into plural blocks and an instruction counter 12 counts the number of instructions in each block and records the numbers on an instruction number table 13. An interrupting instruction giving section 14, on the other hand, outputs an interrupting instruction to a disk device 20. In the moment a CPU 30 loads a program from the device 20 and executes the interrupting instruction, an interruption counter 42 adds '1' to a number of interruption generating times and, when the execution of the program is completed, a counting section 43 reads out the number of interruption generated times and number of instructions at every block and finds the number of executed instructions of each block by multiplication. Therefore, the counted result of the number of executed instructions is obtained at a high speed by reducing the number of interruption generated times.