To easily improve the dimensional accuracy of a wire which is formed by rolling by remarkably reducing variation of the gap between a pair of rolling rolls.

In the nondriven rolling roll device 10 for imparting a prescribed shape by rolling by threading the wire between a pair of the rolling rolls 1, 2 parallel to each other, the dimensions of the max. and min. gaps between the rolling rolls 1, 2 are measured and a position where this gap becomes the average value of these max. and min. dimensions of the gap is determined. A pair of the rolling rolls 1, 2 are connected by transmitting means 16, 17 in this position and a pair of the rolling rolls 1, 2 are rotated at the same angular velocity.