A drum washing machine comprising: a drum; and a drive unit to rotate the drum, wherein the drive unit includes: a motor; a shaft (120, 220, 320, 420, 520) having first and second ends, the first end coupled to a rotor of the motor and the second end coupled to the drum, and transmitting power of the motor to the drum, wherein the shaft (120, 220, 320, 420, 520) comprises: a first bearing and a second bearing located between the first end and the second end; a first bearing mount surface (123, 223, 323, 423, 523) for receiving the first bearing and a second bearing mount surface (124, 424, 524) for receiving the second bearing; a bushing mount surface (125, 225, 325, 425, 525) located between the second end and the bearing mount surface closest to the second end; and a first groove (126, 226, 326, 426) provided on the bushing mount surface (125, 225, 325, 425, 525) to disperse stress concentrated on an edge portion of the shaft (120, 220, 320, 420, 520), wherein the first groove (126, 226, 326, 426) is disposed in a ring shape around the circumference of the shaft (120, 220, 320, 420, 520); and a bushing (150, 450, 550) mounted to the bushing mount surface (125, 225, 325, 425, 525) and arranged to surround at least a portion of the outer surface of the shaft (120, 220, 320, 420, 520) so as to surround the contour of the first groove (126, 226,326, 426). a drum; and a drive unit to rotate the drum, wherein the drive unit includes: a motor; a shaft (120, 220, 320, 420, 520) having first and second ends, the first end coupled to a rotor of the motor and the second end coupled to the drum, and transmitting power of the motor to the drum, wherein the shaft (120, 220, 320, 420, 520) comprises: a first bearing and a second bearing located between the first end and the second end; a first bearing mount surface (123, 223, 323, 423, 523) for receiving the first bearing and a second bearing mount surface (124, 424, 524) for receiving the second bearing; a bushing mount surface (125, 225, 325, 425, 525) located between the second end and the bearing mount surface closest to the second end; and a first groove (126, 226, 326, 426) provided on the bushing mount surface (125, 225, 325, 425, 525) to disperse stress concentrated on an edge portion of the shaft (120, 220, 320, 420, 520), wherein the first groove (126, 226, 326, 426) is disposed in a ring shape around the circumference of the shaft (120, 220, 320, 420, 520); and a bushing (150, 450, 550) mounted to the bushing mount surface (125, 225, 325, 425, 525) and arranged to surround at least a portion of the outer surface of the shaft (120, 220, 320, 420, 520) so as to surround the contour of the first groove (126, 226,326, 426). a motor; a shaft (120, 220, 320, 420, 520) having first and second ends, the first end coupled to a rotor of the motor and the second end coupled to the drum, and transmitting power of the motor to the drum, wherein the shaft (120, 220, 320, 420, 520) comprises: a first bearing and a second bearing located between the first end and the second end; a first bearing mount surface (123, 223, 323, 423, 523) for receiving the first bearing and a second bearing mount surface (124, 424, 524) for receiving the second bearing; a bushing mount surface (125, 225, 325, 425, 525) located between the second end and the bearing mount surface closest to the second end; and a first groove (126, 226, 326, 426) provided on the bushing mount surface (125, 225, 325, 425, 525) to disperse stress concentrated on an edge portion of the shaft (120, 220, 320, 420, 520), wherein the first groove (126, 226, 326, 426) is disposed in a ring shape around the circumference of the shaft (120, 220, 320, 420, 520); and a bushing (150, 450, 550) mounted to the bushing mount surface (125, 225, 325, 425, 525) and arranged to surround at least a portion of the outer surface of the shaft (120, 220, 320, 420, 520) so as to surround the contour of the first groove (126, 226,326, 426). a first bearing and a second bearing located between the first end and the second end; a first bearing mount surface (123, 223, 323, 423, 523) for receiving the first bearing and a second bearing mount surface (124, 424, 524) for receiving the second bearing; a bushing mount surface (125, 225, 325, 425, 525) located between the second end and the bearing mount surface closest to the second end; and a first groove (126, 226, 326, 426) provided on the bushing mount surface (125, 225, 325, 425, 525) to disperse stress concentrated on an edge portion of the shaft (120, 220, 320, 420, 520), wherein the first groove (126, 226, 326, 426) is disposed in a ring shape around the circumference of the shaft (120, 220, 320, 420, 520); and a bushing (150, 450, 550) mounted to the bushing mount surface (125, 225, 325, 425, 525) and arranged to surround at least a portion of the outer surface of the shaft (120, 220, 320, 420, 520) so as to surround the contour of the first groove (126, 226,326, 426).