An apparatus for controlling a refrigerant level, the apparatus comprising: a first detecting unit (110; 210) comprising a first cell (111; 211) installed in a lower part of the inside of a refrigerant tank (101; 201) and having therein a space portion (112; 212), a first cell inner-wall temperature sensor (113; 213) installed at an inner wall of the first cell for measuring a temperature of the first cell, a first heat generation portion (114; 214) installed in the space portion of the first cell at a distance from the first cell inner-wall temperature sensor for transferring heat to the first cell inner-wall temperature sensor, and a first refrigerant temperature sensor (115; 215) detecting a temperature of a refrigerant stored in the lower part of the refrigerant tank; a second detecting unit (120; 220) comprising a second cell (121; 221) installed in an upper part of the refrigerant tank (101; 201) and having therein a space portion (122; 222), a second cell inner-wall temperature sensor (123; 223) installed at an inner wall of the second cell for measuring a temperature of the second cell, a second heat generation portion (124; 224) installed in the space portion of the second cell at a distance from the second cell inner-wall temperature sensor for transferring heat to the second cell inner-wall temperature sensor, and a second refrigerant temperature sensor (125; 225) detecting a temperature of a refrigerant stored in the upper part of the refrigerant tank; a control unit for controlling a refrigerant level within the refrigerant tank according to a difference between a cell inner-wall temperature and a refrigerant temperature measured by each of the first and second detecting units. a first detecting unit (110; 210) comprising a first cell (111; 211) installed in a lower part of the inside of a refrigerant tank (101; 201) and having therein a space portion (112; 212), a first cell inner-wall temperature sensor (113; 213) installed at an inner wall of the first cell for measuring a temperature of the first cell, a first heat generation portion (114; 214) installed in the space portion of the first cell at a distance from the first cell inner-wall temperature sensor for transferring heat to the first cell inner-wall temperature sensor, and a first refrigerant temperature sensor (115; 215) detecting a temperature of a refrigerant stored in the lower part of the refrigerant tank; a second detecting unit (120; 220) comprising a second cell (121; 221) installed in an upper part of the refrigerant tank (101; 201) and having therein a space portion (122; 222), a second cell inner-wall temperature sensor (123; 223) installed at an inner wall of the second cell for measuring a temperature of the second cell, a second heat generation portion (124; 224) installed in the space portion of the second cell at a distance from the second cell inner-wall temperature sensor for transferring heat to the second cell inner-wall temperature sensor, and a second refrigerant temperature sensor (125; 225) detecting a temperature of a refrigerant stored in the upper part of the refrigerant tank; a control unit for controlling a refrigerant level within the refrigerant tank according to a difference between a cell inner-wall temperature and a refrigerant temperature measured by each of the first and second detecting units.