To provide a norbornene polymer which can be used in producing a film having the property of developing a negative Rth, a film using the norbornene type polymer, a polarizing plate using the film, and a liquid crystal display device using the film.

The norbornene type polymer is formed by addition polymerization from a monomer composition comprising at least one kind of norbornene derivatives represented by formula (1) (wherein R1, R2, R3, R4, R5, R6, R7, and R8 are each independently a hydrogen atom or a substituent and n is an integer of 0-2).