ROLL MILL

PROBLEM TO BE SOLVED: To provide a roll mill capable of forming a high quality raw material having optimum paste-like viscosity even when kneading and dispersion processing is carried out for a long time.SOLUTION: The roll mill carries out the kneading and dispersion processing by feeding a paste-like raw material 23 in which a powder material and solvent are mixed between a pair of rolls 10, 11 that are adjacently arranged in axis-parallel. This roll mill includes a casing 13 storing the pair of the rolls and holding air-tightness of a storage space 14 so that the surrounding of the rolls is under a certain atmosphere and a purge means for purging the atmosphere of the storage space in the casing with the vapor atmosphere of the solvent. The purge means includes an exhaust gas path 15 communicated between the storage space and the outside air while interposing an exhaust gas shut-off valve 16 and supply paths 18, 26 communicated between the storage space and a solvent vapor supply means arranged outside while interposing a vapor shut-off valve 19.