Nuts 22, 23 are engaged with one ball screw 10, and the nut 22 is directly fixed on a slider main body 7s. The nut 23 is rotatably held by a bearing 25, and a bearing holder 24 holding the bearing 25 is fixed on a slider main body 7t. And, a gear 26 is fixed on the side of the nut 23, and a gear 29 engaging with the gear 26 is provided. And, a motor 28 for driving a gear 29 is fixed on a bracket 27, being united with the slider main body 7t. The ball screw 10 is stopped and the motor 28 is rotated so as to individually position the slider 7b. Even if the number of the sliders is increased, a machine is not made bigger, and the printed board processing machine having simple structure can be provided.