PURPOSE: To improve the working speed by moving a stylus in Z-axis on the basis of output signal from a multiplier for multiplying the combined displacement from a tracer head by predetermined feed speed.

CONSTITUTION: Upon detection that a stylus 2 has reached to feed position under profiling, feed control circuit 13 will apply signals to feeding speed setting circuit 14 until the stylus 2 is fed in Z direction by predetermined amount while said circuit 14 will keep production of predetermined feeding signals during the time interval when control signals are applied from feed control circuit 11 while to bring the output signal to zero in other time interval. Then a multiplier 15 will multiply the results from an arithmetic unit 12 by the speed signals from the setting circuit 14 to apply the output signals through an amplifier 9Z to a motor 10Z thus to feed the stylus 2 in Z-direction with such speed as corresponding with the multiplification results. In other word, actual feeding speed will change in accordance with the model shape resulting in improvement of working speed.