A condenser dryer includes a drying chamber for items to be dried; a process-air circuit including a fan; and a heat pump in which a refrigerant circulates. The heat pump has an evaporator and a condenser, with the evaporator or the condenser or both being a heat exchanger having level surfaces and including at least one endlessly folded, flattened tube to form a plurality of rows of meander stacks in laterally offset relationship.