A wall-mounted washing machine with a built-in drying device operable to generate hot air during drying processes. The washing machine includes a rear panel configured to be affixed to a wall surface and support the tub. The rear panel includes one or more vent holes that allow hot air existing in a space between the rear panel and the housing of the washing machine to be discharged outside. By promptly removing hot air from the vicinity of the housing, the internal temperature of the washing machine can be effectively controlled and various components in the washing machine can be protected from unintended heating by the hot air.