A composition includes a metal compound and a solvent. The metal compound includes: a plurality of metal atoms of titanium, tantalum, zirconium, tungsten or a combination thereof; oxygen atoms each crosslinking the metal atoms; and polydentate ligands each coordinating to the metal atom. An absolute molecular weight of the metal compound as determined by static light scattering is no less than 8,000 and no greater than 50,000. A pattern-forming method includes applying the composition on an upper face side of a substrate to form an inorganic film. A resist pattern is formed on an upper face side of the inorganic film. The inorganic film and the substrate are dry-etched, by each separate etching operation, using the resist pattern as a mask such that the substrate has a pattern.