Provided is a substrate treating device capable of improving a tact time of a substrate treatment process. A polishing device as the substrate treating device includes a plurality of polishing units (3a, 3b) for polishing a semiconductor wafer (W) and a swing transporter (7) for conveying the wafer (W). The swing transporter (7) includes a wafer grasping mechanism (112) for grasping the wafer (W), a vertical motion mechanism (104, 106) for vertically mobbing the wafer grasping mechanism (112) along a frame (102) of a case of the polishing unit (3a), and a rotary mechanism (108, 110) for rotating the wafer grasping mechanism (112) around an axis adjacent to the frame (102).