The present invention is aim to provide a washing drier which filter case can be assembled and unassembled easily. The washing drier is arranged with a drying filter device which is used to collect flocking in dried air. The washing drier is characterized in that the drying filter device comprises a main body case frame for containing filter case acceptance part and a filter case installed in thefilter case acceptance part, the filter case comprises a supported locking rod which rotates freely, the filter case acceptance part is arranged with a fixing part which makes the locking rod combineor detach through the rotation of the locking rod.