A traverse device and a traverse method for winding wire materials are provided. A guide roller is placed near the outer circumference of a reel body and inclined, around the rotation center (center of curvature of an R guide) located near the outer edge of the guide roller on the side near the reel body as the fulcrum, in a direction in which the roller outer edge recedes from one of reel flanges ahead in the traverse direction on the side apart from the reel body. The inclining direction is switched at the midpoint position between the reel flanges, and with the guide roller being inclined at all times, a reel is rotated while being moved in the axis direction to wind a wire material on the reel.