A washing machine comprising: a body in which an opening (na) is formed; and a door disposed to open and close the opening, wherein the door comprises: a first door member that constitutes a front side of the door, said first door member comprising: a circular guide protrusion arranged to protrude from an edge of a rear side of the first door member; and a plurality of fastening protrusions, wherein each of the plurality of fastening protrusions is formed in a circumferential direction of the first door member and arranged to protrude from an outer side of the guide protrusion; and a second door member that is combined with the first door member and constitutes a rear side of the door, said second door member comprising: a guide groove corresponding to the guide protrusion, wherein the guide protrusion is arranged to be received in the guide groove and the guide protrusion is arrange to guide rotation of the first door member; and a plurality of fastening holes formed to correspond to the plurality of fastening protrusions, wherein the fastening holes are formed spaced apart from each other by a predetermined gap in a circumferential direction of the second door member, and are formed in a L shape along the rotation direction of the second door member, wherein the first door member and the second door member are combined with each other so that the first door member is capable of being rotated relative to the second door member, and the plurality of fastening protrusions is capable of being rotated and inserted into and fixed to the plurality of fastening holes. a body in which an opening (na) is formed; and a door disposed to open and close the opening, wherein the door comprises: a first door member that constitutes a front side of the door, said first door member comprising: a circular guide protrusion arranged to protrude from an edge of a rear side of the first door member; and a plurality of fastening protrusions, wherein each of the plurality of fastening protrusions is formed in a circumferential direction of the first door member and arranged to protrude from an outer side of the guide protrusion; and a second door member that is combined with the first door member and constitutes a rear side of the door, said second door member comprising: a guide groove corresponding to the guide protrusion, wherein the guide protrusion is arranged to be received in the guide groove and the guide protrusion is arrange to guide rotation of the first door member; and a plurality of fastening holes formed to correspond to the plurality of fastening protrusions, wherein the fastening holes are formed spaced apart from each other by a predetermined gap in a circumferential direction of the second door member, and are formed in a L shape along the rotation direction of the second door member, a first door member that constitutes a front side of the door, said first door member comprising: a circular guide protrusion arranged to protrude from an edge of a rear side of the first door member; and a plurality of fastening protrusions, wherein each of the plurality of fastening protrusions is formed in a circumferential direction of the first door member and arranged to protrude from an outer side of the guide protrusion; and a circular guide protrusion arranged to protrude from an edge of a rear side of the first door member; and a plurality of fastening protrusions, wherein each of the plurality of fastening protrusions is formed in a circumferential direction of the first door member and arranged to protrude from an outer side of the guide protrusion; and a second door member that is combined with the first door member and constitutes a rear side of the door, said second door member comprising: a guide groove corresponding to the guide protrusion, wherein the guide protrusion is arranged to be received in the guide groove and the guide protrusion is arrange to guide rotation of the first door member; and a plurality of fastening holes formed to correspond to the plurality of fastening protrusions, wherein the fastening holes are formed spaced apart from each other by a predetermined gap in a circumferential direction of the second door member, and are formed in a L shape along the rotation direction of the second door member, a guide groove corresponding to the guide protrusion, wherein the guide protrusion is arranged to be received in the guide groove and the guide protrusion is arrange to guide rotation of the first door member; and a plurality of fastening holes formed to correspond to the plurality of fastening protrusions, wherein the fastening holes are formed spaced apart from each other by a predetermined gap in a circumferential direction of the second door member, and are formed in a L shape along the rotation direction of the second door member, wherein the first door member and the second door member are combined with each other so that the first door member is capable of being rotated relative to the second door member, and the plurality of fastening protrusions is capable of being rotated and inserted into and fixed to the plurality of fastening holes.