A washing machine comprising: a housing; a drum rotatably disposed inside the housing; and a filter assembly configured to be attached to an inner circumferential wall of the drum to filter water inside the drum, during a rotation of the drum, by passing water through the filter assembly in a manner that water flowing in a circumferential direction of the drum, opposite a direction of the rotation of the drum, enters the filter assembly, passes through the filter assembly, and is discharged from the filter assembly in a radial direction of the drum towards a center of rotation of the drum, wherein the filter assembly includes: a first opening that, while the filter assembly is attached to the inner circumferential wall of the drum, is on a first circumferential side of the filter assembly with respect to the circumferential direction of the drum; a discharge portion configured to, while the filter assembly is attached to the inner circumferential wall of the drum, discharge the water, flowing through the first opening, in the radial direction of the drum towards the center of rotation of the drum; and a second opening on a second circumferential side of the filter assembly opposite to the first opening; a first valve member configured to allow the water flowing through the first opening to flow into the discharge portion, and a second valve member configured to allow the water flowing through the second opening to flow into the discharge portion, wherein the first valve member prevents the washing water flowing into the filter assembly, from the second opening, from flowing into the first opening; characterized in that the first valve member is configured to guide the washing water toward the discharge portion. a housing; a drum rotatably disposed inside the housing; and a filter assembly configured to be attached to an inner circumferential wall of the drum to filter water inside the drum, during a rotation of the drum, by passing water through the filter assembly in a manner that water flowing in a circumferential direction of the drum, opposite a direction of the rotation of the drum, enters the filter assembly, passes through the filter assembly, and is discharged from the filter assembly in a radial direction of the drum towards a center of rotation of the drum, wherein the filter assembly includes: a first opening that, while the filter assembly is attached to the inner circumferential wall of the drum, is on a first circumferential side of the filter assembly with respect to the circumferential direction of the drum; a discharge portion configured to, while the filter assembly is attached to the inner circumferential wall of the drum, discharge the water, flowing through the first opening, in the radial direction of the drum towards the center of rotation of the drum; and a second opening on a second circumferential side of the filter assembly opposite to the first opening; a first valve member configured to allow the water flowing through the first opening to flow into the discharge portion, and a second valve member configured to allow the water flowing through the second opening to flow into the discharge portion, wherein the first valve member prevents the washing water flowing into the filter assembly, from the second opening, from flowing into the first opening; characterized in that the first valve member is configured to guide the washing water toward the discharge portion. a first opening that, while the filter assembly is attached to the inner circumferential wall of the drum, is on a first circumferential side of the filter assembly with respect to the circumferential direction of the drum; a discharge portion configured to, while the filter assembly is attached to the inner circumferential wall of the drum, discharge the water, flowing through the first opening, in the radial direction of the drum towards the center of rotation of the drum; and a second opening on a second circumferential side of the filter assembly opposite to the first opening; a first valve member configured to allow the water flowing through the first opening to flow into the discharge portion, and a second valve member configured to allow the water flowing through the second opening to flow into the discharge portion, wherein the first valve member prevents the washing water flowing into the filter assembly, from the second opening, from flowing into the first opening; characterized in that the first valve member is configured to guide the washing water toward the discharge portion.