A clothes treatment apparatus includes a tub to store water, a drum rotatably arranged in the tub to accommodate clothes, a communication tube communicated with the tub, a pressure in the communication tube corresponding to a water level of the tub, and a chamber provided at a free end of the communication tube so that a pressure in the chamber corresponds to a water level of the tub. An elastic part is provided in the chamber and elastically deformed according to a change in pressure in the communication tube. An output unit having a plurality of resistors is provided on one surface of the elastic part to generate an electrical signal corresponding to an amount of deformation of the elastic part, and a controller is configured to receive the electrical signal and sense the water level of the tub by comparing the electrical signal of the output unit with a reference electrical signal indicating a zero water level of the tub.