A dishwasher comprising: a tub configured to receive objects to be washed; a spray arm configured to spray wash water to the objects to be washed; a sump configured to store wash water; and a pump configured to supply the wash water stored in the sump to the spray arm, wherein the pump comprises: a body; a partition wall configured to divide an interior of the body into two spaces; a first chamber located under the partition wall, the first chamber having an introduction portion communicating with the sump; a second chamber located above the partition wall, the second chamber having a discharge portion communicating with the spray arm; a communication hole formed through the partition wall to allow the first chamber and the second chamber to communicate with each other therethrough; an impeller provided in the second chamber to move wash water to the discharge portion; a heater assembly separately coupled to an opening surface provided at a lower part of the body, the heater assembly including a housing configured to close the opening surface and form the bottom surface of the first chamber, and a heater provided outside of the first chamber and configured to heat the housing, the housing being made of a conductor such that thermal energy generated by the heater can be effectively supplied to wash water in the first chamber. a tub configured to receive objects to be washed; a spray arm configured to spray wash water to the objects to be washed; a sump configured to store wash water; and a pump configured to supply the wash water stored in the sump to the spray arm, wherein the pump comprises: a body; a partition wall configured to divide an interior of the body into two spaces; a first chamber located under the partition wall, the first chamber having an introduction portion communicating with the sump; a second chamber located above the partition wall, the second chamber having a discharge portion communicating with the spray arm; a communication hole formed through the partition wall to allow the first chamber and the second chamber to communicate with each other therethrough; an impeller provided in the second chamber to move wash water to the discharge portion; a heater assembly separately coupled to an opening surface provided at a lower part of the body, the heater assembly including a housing configured to close the opening surface and form the bottom surface of a body; a partition wall configured to divide an interior of the body into two spaces; a first chamber located under the partition wall, the first chamber having an introduction portion communicating with the sump; a second chamber located above the partition wall, the second chamber having a discharge portion communicating with the spray arm; a communication hole formed through the partition wall to allow the first chamber and the second chamber to communicate with each other therethrough; an impeller provided in the second chamber to move wash water to the discharge portion; a heater assembly separately coupled to an opening surface provided at a lower part of the body, the heater assembly including a housing configured to close the opening surface and form the bottom surface of the first chamber, and a heater provided outside of the first chamber and configured to heat the housing, the housing being made of a conductor such that thermal energy generated by the heater can be effectively supplied to wash water in the first chamber.