An air purifier includes a pump that supplies air to an air purifying unit, a filter arranged at an outlet of the air purifying unit, and pipes and that connect these components. The air purifying unit includes an activated carbon tube constituted by a glass tube filled with granular activated carbon, and a soda lime tube constituted by a glass tube filled with granular soda lime. According to a preferred embodiment, three each of the activated carbon tubes and the soda lime tubes are provided, and the activated carbon tubes and the soda lime tubes are connected alternately in series by tubes so that one activated carbon tube is arranged at a most upstream part and one soda lime tube is arranged at a most downstream part.