It is an object of the present invention to provide a negative photoresist composition for lithography, using short-wavelength light such as ArF excimer laser beam as a light source. The negative photoresist composition of the present invention is a negative photoresist composition comprising at least a polymer having a unit represented by the general formula (1) a crosslinking agent and a photo-acid generating agent, and the crosslinking agent is capable of crosslinking the polymer in the presence of an acid catalyst, whereby the polymer is insolubilized in a developer. Since the negative resist composition of the present invention is insolubilized in the developer by an action of an acid produced from the photo-acid generating agent at the exposed portion, a negative pattern can be obtained. Since the polymer has not a benzene ring, unlike a base polymer of a conventional negative resist, the polymer has high transparency to ArF excimer laser beam and also has high etching resistance because of its bridged alicyclic group.