An apparatus for treating clothes includes an accommodating space, an air supply unit, a duct unit, a filter unit, a substance removal unit and a collection unit that is separate from the filter unit and the substance removal unit. The accommodating space is configured to receive one or more clothing articles. The air supply unit is configured to supply air to the accommodating space. The duct unit is configured to guide discharge of air from the accommodating space. The filter unit is positioned to filter substances from air discharged from the accommodating space through the duct unit. The substance removal unit is configured to move substances remaining on a portion of the filter unit. The collection unit is configured to collect substances moved from the filter unit by the substance removal unit.