There is disclosed a patterning process comprises at least (1) a step of forming an organic underlayer film on a substrate and then forming a photoresist pattern on the organic underlayer film, (2) a step of attaching an alkaline solution containing an alkaline substance onto the photoresist pattern and then removing the excess alkaline solution, (3) a step of applying a solution of a siloxane polymer crosslinkable by action of the alkaline substance onto the photoresist pattern to form a crosslinked part by crosslinking the siloxane polymer near the photoresist patterns, and (4) a step of removing the uncrosslinked siloxane polymer and the photoresist pattern. There can be provided a patterning process capable of forming a further finer pattern simply and efficiently and with a high practicability applicable to semiconductor manufacturing.