A dishwasher comprising: a tub defining a washing space and accommodating dishes; and a heat pump apparatus configured to heat wash water introduced into the tub, wherein the heat pump apparatus comprises, a compressor configured to compress refrigerant; a first heat exchanger to which refrigerant is introduced from the compressor when the dishwasher performs a washing mode, the first heat exchanger configured to heat water introduced into the tub; a first expansion valve to which refrigerant is introduced from the first heat exchanger when the dishwasher performs the washing mode, the first expansion valve configured to expand refrigerant; a second heat exchanger to which refrigerant is introduced from the first expansion valve; characterized in that the heat pump apparatus further comprises: a second expansion valve disposed in parallel with the first expansion valve, the second expansion valve to which refrigerant is introduced from the first heat exchanger when the dishwasher performs the washing mode; J Z a third heat exchanger disposed in parallel with the second heat exchanger, the third heat exchanger to which refrigerant is introduced from the second expansion valve when the dishwasher performs the washing mode; J Z and a four way valve connected with the compressor, the first heat exchanger, the second heat exchanger and the third heat exchanger and configured to change a flow path of a refrigerant. a tub defining a washing space and accommodating dishes; and a heat pump apparatus configured to heat wash water introduced into the tub, wherein the heat pump apparatus comprises, a compressor configured to compress refrigerant; a first heat exchanger to which refrigerant is introduced from the compressor when the dishwasher performs a washing mode, the first heat exchanger configured to heat water introduced into the tub; a first expansion valve to which refrigerant is introduced from the first heat exchanger when the dishwasher performs the washing mode, the first expansion valve configured to expand refrigerant; a second heat exchanger to which refrigerant is introduced from the first expansion valve; characterized in that the heat pump apparatus further comprises: a second expansion valve disposed in parallel with the first expansion valve, the second expansion valve to which refrigerant is introduced from the first heat exchanger when the dishwasher performs the washing mode; J Z a third heat exchanger disposed in parallel with the second heat exchanger, the third heat exchanger to which refrigerant is introduced from the second expansion valve when the dishwasher performs the washing mode; J Z and a four way valve connected with the compressor, the first heat exchanger, the second heat exchanger and the third heat exchanger and configured to change a flow path of a refrigerant. a second expansion valve disposed in parallel with the first expansion valve, the second expansion valve to which refrigerant is introduced from the first heat exchanger when the dishwasher performs the washing mode; J Z a third heat exchanger disposed in parallel with the second heat exchanger, the third heat exchanger to which refrigerant is introduced from the second expansion valve when the dishwasher performs the washing mode; J Z and a four way valve connected with the compressor, the first heat exchanger, the second heat exchanger and the third heat exchanger and configured to change a flow path of a refrigerant.