(57) The present invention provides a dehumidifier, including a main body (2), comprising a dehumidification passage in which indoor air is sucked in and the sucked-in indoor air is dehumidified and a reconditioning passage in which reconditioning air circulates, a dehumidification rotor (60), comprising a dehumidification portion configured to dehumidify the indoor air and a reconditioning portion reconditioned using the reconditioning air, and a condensing heat exchanger (200) in which a plurality of heat exchange plates (220,240,260), each comprising a plurality of condensing ducts (232,253,272), is arranged in parallel. The condensing ducts are configured so that the reconditioning air passed through the reconditioning portion is sucked in through upper parts of the condensing ducts and the sucked-in reconditioning air is discharged through lower parts of the condensing ducts. Thus, the flow of air within the condensing heat exchanger can become uniform and the heat exchange area is widened. Accordingly, the dehumidification performance of the dehumidifier can be improved and noise caused when the dehumidifier is driven can be reduced.