To provide an inexpensive substrate transport mechanism, transporting a substrate with high accuracy in a predetermined region between a plurality of processing parts, and a coating film forming device having it.

A resist coater CT 23a includes: a substrate carry-in part 5a for carrying in the substrate G; a coating part 5b for supplying resist liquid to the substrate G to form a coating film; a substrate carry-out part 5c for carrying out a substrate G on which the coating film is formed; and a substrate transport mechanism 13 for transporting the substrate G from the substrate carry-in part 5a to the substrate carry-out part 5c substantially horizontally in one direction. As a linear scale used for controlling the transport of the substrate transport mechanism 13, a second scale 55b having high resolving power is used while the resist liquid is supplied to the substrate G, and a first scale 55a/55c having lower resolving power than the second scale 55b is used in the regions outside of that. The scales are thus switched between them.