Abstract: In a humidifier, its humidifier body is formed as follows: A plurality of ribs 3 made of a flexible material are fixedly adhered to the inner surface 1a of a tubular film structure 1 made of a moisture permeable film 2 in such a manner that the ribs are extended in parallel with the longitudinal axis of the tubular film structure, and the tubular film structures 1 and spacer boards 4 adapted to form spaces outside the tubular film structures into which air is supplied, are alternately laid one on another. Whereby, it is provided a humidifier which is excellent in water supply characteristic, high in humidification, and low in air resistance.