It is an object of the present invention to provide a water repellant composition for a substrate to be exposed which inhibits the back side of a substrate to be exposed from being contaminated by an immersion liquid, can improve adhesion between a film to be processed and an organic film directly overlying that film to inhibit film peeling, and has excellent workability, a method for forming a resist pattern, an electronic device produced by the formation method, a treatment method for imparting water repellency to a substrate to be exposed, a water repellent set for a substrate to be exposed, and a treatment method for imparting water repellency to a substrate to be exposed using the same. A water repellent composition for a substrate to be exposed including at least an organosilicon compound represented by the following general formula (1) and a solvent is used. In the formula, R1 is a monovalent organic group having 14 to 30 carbon atoms, each R2, R3, and R4 is independently a monovalent organic group or a hydrolyzable group having 1 to 10 carbon atoms, and at least one of R2, R3, and R4 is a hydrolyzable group.