A washing machine includes a housing; a drum disposed inside the housing and including a rotation shaft that extends in a vertical direction; and a filter unit disposed at an inner wall of the drum, configured to filter washing water flowing in a circumferential direction of the drum and to discharge the washing water in a radial direction inside of the drum. Accordingly, when a water current is formed inside the drum in the circumferential direction of the drum, the filter unit is disposed inside the drum so that foreign substances in the washing water rotated in the circumferential direction of the drum can be easily filtered.