Laundry dryer and laundry dryer control method

A method for controlling a laundry dryer, the laundry dryer including a cabinet that defines an outer appearance of the laundry dryer, a drum disposed inside the cabinet and configured to accommodate an object to be dried therein, a duct assembly configured to circulate air discharged from the drum to the drum, a circulation fan configured to provide a flow force to the air moving along the duct assembly, a heat exchange assembly disposed in the duct assembly and configured to exchange heat with the air circulated along the duct assembly, and a compressor configured to compress a refrigerant to exchange heat with the air circulated along the duct assembly, and a steam device configured to supply steam into the drum, the method comprising:

• increasing a temperature inside the cabinet for sterilization of the drum;
• supplying steam into the drum for sterilization of the drum after increasing the temperature inside the cabinet;
• and
• circulating air inside the drum after supplying the steam into the drum,
• wherein increasing the temperature inside the cabinet, supplying the steam into the drum, and circulating the air inside the drum are performed while rotating the drum based on no laundry load being applied to the drum,
• wherein increasing the temperature inside the cabinet and circulating the air inside the drum are performed while operating the circulation fan,
• wherein supplying the steam into the drum is performed while the circulation fan is stopped, and
• wherein circulating the air inside the drum comprises operating a drain pump to thereby drain condensate water collected in the cabinet.