To suppress the intrinsic vabration of a reciprocating device of long size rod such as a traverse device effectively.

This device is provided with a vibration suppressing means 17 to suppress the vibration in the reciprocating direction by operation in the reciprocating direction of a long size rod 13. As the vibration suppressing means 17, a vibration absorber which consists of an visco-elastic body 17b extending and contracting in the reciprocating direction, and a weight 17a installed to the visco-elastic body 17b, is favorable to be used, and it is favorable to house this vibration absorber by dispersing, at the free end side A1 at the front end, inside a hollow pipe form of rod.