PURPOSE: To obtain a simple and downsized wire length measuring apparatus in which two carriers, each having a gripper, are controlled by means of a single shaft control unit and a drive motor.

CONSTITUTION: Carriers 2A, 2B, arranged movably along parallel. linear guides 1A, 1B, are provided with grippers 17A, 17B and one of ball screws 3A, 3B, arranged on the outside of the guides in parallel therewith, is provided with a coupling clutch 6. Both ball screws are provided with two gears 8, 9 meshing therewith and both ball screws are rotated oppositely through a single drive motor 5 under control of an NC unit 10 to move the grippers in the opposite directions. A wire 11 is gripped at a reference position X0 and an operation for drawing the wire by an amount L1, corresponding to desired length divided by an integer, at a time is repeated until a length measuring point X1 is reached. When the distance L1 is varied to obtain a desired measurement, the coupling clutch 6 is released and rotation of one ball screw is stopped and then the distance L1 is regulated.