PROBLEM TO BE SOLVED: To attain the removal of odor caused by smog and particulates and the prevention of indoor browning and browning of furniture by inexpensively and simply removing the smog of an odor substance and its particulates floating indoors and cleaning indoor air.SOLUTION: A method for cleaning indoor air by using sulfamic acid is the method for removing basic smog or particulates floating in the air by making the air containing basic smog or particulates be brought into contact with a base that is constituted of paper, fabric, and non-woven fabric, etc. and impregnated with a sulfamic acid aqueous solution. A moisture absorption agent is included, that is necessary to prevent a sulfamic acid aqueous solution from being dried. In this case, a surfactant, etc., may be included in order to uniformly impregnate the base with a sulfamic acid aqueous solution, and also the surface area of the base may be enlarged by making the base have a bellows or honeycomb shape.
