A substrate processing system according to one embodiment is equipped with a plurality of trays, a processing head, and a plurality of linear assist units. Substrates can be held by the plurality of trays. The processing head processes the substrate in a processing chamber. The plurality of linear assist units convey the plurality of trays in the conveyance direction in the processing chamber so that the substrates are processed by the processing head. Each of the plurality of linear assist units includes: a linear guide that extends in the conveyance direction and has a stator for a linear motor arranged in the conveyance direction; and a movable body that moves along the linear guide. The linear guides of the plurality of linear assist units are arranged in a direction intersecting the conveyance direction. Each movable body of the plurality of linear assist units is capable of selectively coupling to the tray that is accommodated in the processing chamber among the plurality of trays, and said movable body includes a coupling unit capable of releasing the tray.