The present invention relates to a laundry machine, and more particularly, to an apparatus for treating a laundry, by which a laundry can be treated in a manner of hanging the laundry or the like with a cabinet type body. The present invention includes a cabinet comprising an accommodating space and a mechanism compartment partitioned from the accommodating space by a partition, a steam generator configured to generate steam to be supplied to the accommodating space, and a steam supply unit configured to pass through the partition, the steam supply unit comprising a rotating nozzle to supply steam into the accommodating space.