The present invention relates to a drum washing machine that can be achieved simplification of the manufacture of the case to adopt a structure for transmitting to the drum and then through the planetary gear mechanism decelerates the rotation of the drive motor, a planetary gear mechanism. Drum washing machine according to the present invention by passing to the drum and then through the planetary gear mechanism decelerates the rotation of the drive motor to rotate the rotating drum and having a projection at a different rotational speed from each other. The planetary gear mechanism includes a sun gear, an internal gear, a plurality of planet gears 430 and the planetary gear carrier (440). Planet gear carrier 440 has rear planetary carrier 442 and the front planet carrier 441 is sandwiched between a plurality of planet gears 430 on both sides; And I 2 is interposed between the one and then the planet carrier, and a support shaft 443 which is mounted the planetary gear 430 to be rotatable. A support shaft (443) has its base end before being mounted on the planetary gear 430 is fixed to the rear planetary carrier 442. In addition, the front planet carrier 441 is fixed to the front end portion (443a) of the support shaft (443) equipped with a planetary gear 430.