An air purifier (10, 510), comprising: an air purification filter (20, 520) configured to pass air therethrough in the vertical direction and remove dust contained in the air; a humidification unit (30, 530) including a humidification element (33, 533) configured to vaporize water supplied and humidify the air; an air-blowing fan (12a, 512a) configured to blow air; and a casing (11, 511) accommodating the humidification unit, the air purification filter and the air-blowing fan, an opening (15, 515) being formed on the casing, characterized in that: the air-blowing fan, the air purification filter, and the humidification unit are arranged in the stated order from below inside the casing; the casing is configured such that the opening allows the humidification unit and the air purification filter to be detached via the opening; the air-blowing fan is configured to blow air to the air purification filter and the humidification unit; the humidification unit is disposed in alignment with the air purification filter on a downstream side of the air purification filter with respect to a movement route through which the air purification filter is detached, and disposed above the air purification filter; and the casing is configured such that the opening allows the air purification filter to be detached after the humidification unit has been detached. an air purification filter (20, 520) configured to pass air therethrough in the vertical direction and remove dust contained in the air; a humidification unit (30, 530) including a humidification element (33, 533) configured to vaporize water supplied and humidify the air; an air-blowing fan (12a, 512a) configured to blow air; and a casing (11, 511) accommodating the humidification unit, the air purification filter and the air-blowing fan, an opening (15, 515) being formed on the casing, characterized in that: the air-blowing fan, the air purification filter, and the humidification unit are arranged in the stated order from below inside the casing; the casing is configured such that the opening allows the humidification unit and the air purification filter to be detached via the opening; the air-blowing fan is configured to blow air to the air purification filter and the humidification unit; the humidification unit is disposed in alignment with the air purification filter on a downstream side of the air purification filter with respect to a movement route through which the air purification filter is detached, and disposed above the air purification filter; and the casing is configured such that the opening allows the air purification filter to be detached after the humidification unit has been detached. the air-blowing fan, the air purification filter, and the humidification unit are arranged in the stated order from below inside the casing; the casing is configured such that the opening allows the humidification unit and the air purification filter to be detached via the opening; the air-blowing fan is configured to blow air to the air purification filter and the humidification unit; the humidification unit is disposed in alignment with the air purification filter on a downstream side of the air purification filter with respect to a movement route through which the air purification filter is detached, and disposed above the air purification filter; and the casing is configured such that the opening allows the air purification filter to be detached after the humidification unit has been detached.