To provide a filter capable of being regenerated even in a line that is used in a production process for a semiconductor or liquid crystal and can remove basic compounds such as ammonia contained as impurities in high pressure gases of a low dew point such as compressed air and a compressed inert gas without causing secondary pollution by the filter itself.

The filter is fabricated by loading a casing 1 with a filter material 2 containing as a component a solid acidic porous material selected from the group consisting of H-Y type zeolite, H-mordenite, H-ferrierite, H-ZSM-5, H-beta, Al-silicate, Ga-silicate, Fe-silicate, B-silicate, Al-MCM-41 and Ga-MCM-41, and used in a purge line of the high pressure gases of a low dew point.