A resist pattern thickening material has resin, a crosslinking agent and a compound having a cyclic structure, or resin having a cyclic structure at a part. A resist pattern has a surface layer on a resist pattern to be thickened with etching rate (nm/s) ratio of the resist pattern to be thickened the surface layer of 1.1 or more, under the same condition, or a surface layer to a resist pattern to be thickened. A process for forming a resist pattern includes applying the thickening material after forming a resist pattern to be thickened on its surface. A semiconductor device has a pattern formed by the resist pattern. A process for manufacturing the semiconductor device has applying, after forming a resist pattern to be thickened, the thickening material to the surface of the resist pattern to be thickened, and patterning the underlying layer by etching, the pattern as a mask.