PURPOSE: To eliminate the impact that is produced when a touch probe contacts with an object to be measured and to prevent an error generated during the detection, by setting a deceleration start point at the front side of the target position of measurement and giving deceleration in response to the shifting extent of the touch probe.

CONSTITUTION: The deceleration start point where a feed motor 13 is decelerated at the front side of the target position and a contact is secured between a touch probe 15 and an object to be measured is preset at a setting circuit 19. The information of a command tape 1 is read by a tape reader 2 and then preset at a numerical register 4 and a register 5 via a decoder 3. The motor 13 is started by a control circuit 6. The position of a probe 15 which is shifted by a feed screw 14 is detected by a position detector 16 and counted by a counter 17 to be compared at a comparator 18 with the reference value given from the circuit 19. When a coincidence signal is detected, a low-speed oscillator 9 is actuated by the circuit 6. Then the probe 15 is decelerated via an output circuit 12 to contact with the object to be measured with no impact.