Disclosed is an air cleaner which includes a portable casing, a blowing means (44), a deodorizing element (62) and a control means (47). The portable casing includes therein an air trunk (R) having an inlet (11) and an outlet (42). The blowing means is provided in the casing and blows air introduced from the inlet, into the air trunk, and towards the outlet. The deodorizing element is provided to interrupt the air trunk and through which the air introduced into the air trunk passes. The deodorizing element comprises a catalyst which adsorbs the ammonia component of the air. The control means can control the operation of the blowing means such that the flow rate of the air passing through the deodorizing element is a predetermined value or less. Thus, the deodorizing element collects at least 70% of the ammonia component in the indoor air introduced into the air trunk. Alternatively, the control means controls the flow rate of the air passing through the deodorizing element such that at least one fifth of the volume of the indoor space, which the air cleaner is deodorizing, passes through the element every minute.
