Abstract: An electric steam humidifier of the type which includes electrodes (58, 59) immersed in a tank containing water (5) includes an upper portion (10) consisting of a housing (3) closed by a cover (2), a lower portion (11) consisting of a housing (6) placed on a base (7), with the housings (3) and (6) being identical and positioned symmetrically in relation to a horizontal plane. The housings are joined to a structural element (4) made of aluminum and approximately U-shaped, with the arms of the U forming a space (40) for receiving the tank. The housing (3) contains a compartment (36) into which water is supplied and which includes an aperture (37) for evacuation of steam and an aperture (35) which is fitted to a filling aperture (54) on the upper surface of the tank (5). The tank includes on one of its side surfaces below the medial plane of the tank but above its bottom with a drainage aperture (55).