A refrigerator comprising: a heat exchanger comprising a refrigerant tube in which a refrigerant flows and a heat exchange fin into which the refrigerant tube is inserted; a temperature sensor disposed on an inlet-side or outlet-side of the heat exchanger to detect a temperature of the refrigerant; and a fixing device (100; 300; 400; 500; 600; 700) for fixing a guide tube disposed on an inlet-side or outlet-side of the refrigerant tube and the temperature sensor in a state where the guide tube is in contact with the temperature sensor; wherein the fixing device (300; 400; 500; 600; 700) comprises: a first fixing part (320; 410; 510; 610; 710) coupled to the guide tube; and a second fixing part (330; 420; 520; 620; 720) coupled to the first fixing part (320; 410; 510; 610; 710) to support the guide tube and the temperature sensor so that the guide tube and the temperature sensor contact each other; characterized by a first recess part (324; 415; 515; 615; 715) provided in the first fixing part 320; 410; 510; 610; 710) to support at least one portion of an outer circumferential surface of the guide tube; and a second recess part (324a; 425; 525; 625; 725) provided in the second fixing part (330; 420; 520; 620; 720) to support the other portion of the outer circumferential surface of the guide tube; wherein the second fixing part (330; 420; 520; 620; 720) further comprises a sensor recess part (334; 427; 527; 627; 727) that is further recessed from the second recess part (324a; 425; 525; 625; 725) to accommodate the temperature sensor. a heat exchanger comprising a refrigerant tube in which a refrigerant flows and a heat exchange fin into which the refrigerant tube is inserted; a temperature sensor disposed on an inlet-side or outlet-side of the heat exchanger to detect a temperature of the refrigerant; and a fixing device (100; 300; 400; 500; 600; 700) for fixing a guide tube disposed on an inlet-side or outlet-side of the refrigerant tube and the temperature sensor in a state where the guide tube is in contact with the temperature sensor; wherein the fixing device (300; 400; 500; 600; 700) comprises: a first fixing part (320; 410; 510; 610; 710) coupled to the guide tube; and a second fixing part (330; 420; 520; 620; 720) coupled to the first fixing part (320; 410; 510; 610; 710) to support the guide tube and the temperature sensor so that the guide tube and the temperature sensor contact each other; characterized by a first recess part (324; 415; 515; 615; 715) provided in the first fixing part 320; 410; 510; 610; 710) to support at least one portion of an outer circumferential surface of the guide tube; and a second recess part (324a; 425; 525; 625; 725) provided in the second fixing part (330; 420; 520; 620; 720) to support the other portion of the outer circumferential surface of the guide tube; wherein the second fixing part (330; 420; 520; 620; 720) further comprises a sensor recess part (334; 427; 527; 627; 727) that is further recessed from the second recess part (324a; 425; 525; 625; 725) to accommodate the temperature sensor. a first fixing part (320; 410; 510; 610; 710) coupled to the guide tube; and a second fixing part (330; 420; 520; 620; 720) coupled to the first fixing part (320; 410; 510; 610; 710) to support the guide tube and the temperature sensor so that the guide tube and the temperature sensor contact each other; characterized by a first recess part (324; 415; 515; 615; 715) provided in the first fixing part 320; 410; 510; 610; 710) to support at least one portion of an outer circumferential surface of the guide tube; and a second recess part (324a; 425; 525; 625; 725) provided in the second fixing part (330; 420; 520; 620; 720) to support the other portion of the outer circumferential surface of the guide tube; wherein the second fixing part (330; 420; 520; 620; 720) further comprises a sensor recess part (334; 427; 527; 627; 727) that is further recessed from the second recess part (324a; 425; 525; 625; 725) to accommodate the temperature sensor.