A filter device includes: a filter unit including a housing in which a roll filter stretched between a feeding shaft and a take-up shaft is housed, the housing including, between the two shafts, an opening for exposing a part of the filter; a filter installation detection sensor for detecting installation of the filter unit; a filter winding driving unit for taking up or rewinding the installed filter; and a control unit for controlling operations of the filter winding driving unit based on a detection signal from the filter installation detection sensor. When the control unit determines based on the detection signal from the filter installation detection sensor that the filter is installed, the control unit causes the filter winding driving unit to rewind the filter by a predetermined amount and determines whether the filter is new or not based on the rewinding. By detecting filter replacement, information on the replaced filter can be reset.