A clothes treatment apparatus includes a cabinet, a door, and a steam unit. The clothes treatment apparatus further includes a heat pump unit that is located in the cycle chamber and that is configured to circulate and condition air in the treatment chamber. The clothes treatment apparatus further includes a water supply tank that is installed in the tank installation space, that is connected to the steam unit, and that is configured to supply water to the steam unit. The clothes treatment apparatus further includes a drainage tank that is separably installed in the tank installation space, that is configured to store condensed water generated in at least one of the treatment chamber or the heat pump unit. The clothes treatment apparatus further includes a water supply level sensor. The clothes treatment apparatus further includes a drainage level sensor.