To provide a resist composition for negative type development superior in pattern collapse performance and trench pattern resolution in patterning with negative type development in order to stably form a highly precise fine pattern for manufacturing a highly integrated and highly precise electronic device, and to provide a pattern forming method using the same.

The resist composition for negative type development contains (A) a resin for reducing solubility to a negative type developer due to action of acid by including an acid decomposition repeating unit of a specific structure, (B) a photoacid generator, and (C) a solvent. The pattern forming method using it is also provided.