Provided in the present invention is an apparatus for treating clothing comprising: a cabinet in which a clothing accommodation space for accommodating clothing is formed; a housing detachably coupled to an inner wall of the clothing accommodation space and provided with a purifying space communicating with the clothing accommodation space; a photocatalyst containing a photocatalytic material and provided inside the housing; and a light source assembly, provided inside the housing, for irradiating light including UV rays by penetrating through the purifying space.