A plate material vertical processing line that is capable of subjecting large-sized and thinned glass plates to scribing, venting, etc without degrading their quality, comprises a plurality of processing devices each having a modular structure; wherein each of the processing devices includes a platform; a belt conveyor that is mounted on the platform and is configured to convey a glass plate placed in a substantially upright position while supporting a lower end of the glass plate; and a fluid guide that is mounted on the platform and is configured to apply a fluid pressure to a surface of the glass plate to support the glass plate in the substantially upright position and in a non-contact state; and wherein the processing devices include a combination of at least two processing devices selected from a scribing device, a venting device, a chamfering device, a cleaning agent washing device, a water washing device, a high-pressure water spray device, and a glass plate turn device.