To provide a sheet substrate conveying apparatus applicable to not only a wet conveying apparatus such as a development device but also a dry conveying apparatus such as a process device and an inspection device by applying a sheet conveying unit capable of constructing a constitution for periodically and automatically cleaning a substrate contact member at low cost.

The sheet substrate conveying apparatus carries a substrate on an upper side of a loop-shaped wire of a conveying unit formed by stretching a plurality of wires parallel to each other in the conveying direction between shafts to be driven in a loop shape, and carries the substrate by driving the loop-shaped wire, and has an automatic cleaning mechanism for cleaning the wire during the rotational drive at the position not in contact with the substrate below a loop-shaped wire conveying unit.