An air conditioner comprising: a compressor for compressing an inflow refrigerant to discharge the compressed refrigerant; an outdoor heat exchanger in which outdoor air introduced into an outdoor unit and the refrigerant are heat-exchanged with each other; an indoor heat exchanger in which indoor air introduced into an indoor unit and the refrigerant are heat-exchanged with each other; valves (140, 220, 250, 260) respectively disposed in an inflow-side tube and a discharge-side tube of the indoor heat exchanger, the valves comprising: a first valve disposed in the inflow-side tube of the indoor heat exchanger; and a second valve disposed in the discharge-side tube of the indoor heat exchanger; a refrigerant leakage detection part for directly or indirectly detecting leakage of the refrigerant; and characterized by a control part (600, 700, 800, 900) being configured, when the leakage of the refrigerant is detected, to block at least one of the first and second valves (140, 220, 250, 260), and wherein the control part determines whether a leakage detection time t of the refrigerant exceeds a first reference time t1 when the leakage of the refrigerant is detected, when the leakage detection time t exceeds the first detection time t1, the control part controls that the first valve is blocked, and when the leakage of the refrigerant continues for a second time t2 after the first valve is blocked, the control part controls that the second valve is blocked. a compressor for compressing an inflow refrigerant to discharge the compressed refrigerant; an outdoor heat exchanger in which outdoor air introduced into an outdoor unit and the refrigerant are heat-exchanged with each other; an indoor heat exchanger in which indoor air introduced into an indoor unit and the refrigerant are heat-exchanged with each other; valves (140, 220, 250, 260) respectively disposed in an inflow-side tube and a discharge-side tube of the indoor heat exchanger, the valves comprising: a first valve disposed in the inflow-side tube of the indoor heat exchanger; and a second valve disposed in the discharge-side tube of the indoor heat exchanger; a refrigerant leakage detection part for directly or indirectly detecting leakage of the refrigerant; and characterized by a control part (600, 700, 800, 900) being configured, when the leakage of the refrigerant is detected, to block at least one of the first and second valves (140, 220, 250, 260), and wherein the control part determines whether a leakage detection time t of the refrigerant exceeds a first reference time t1 when the leakage of the refrigerant is detected, when the leakage detection time t exceeds the first detection time t1, the control part controls that the first valve is blocked, and when the leakage of the refrigerant continues for a second time t2 after the first valve is blocked, the control part controls that the second valve is blocked. a first valve disposed in the inflow-side tube of the indoor heat exchanger; and a second valve disposed in the discharge-side tube of the indoor heat exchanger; a refrigerant leakage detection part for directly or indirectly detecting leakage of the refrigerant; and characterized by a control part (600, 700, 800, 900) being configured, when the leakage of the refrigerant is detected, to block at least one of the first and second valves (140, 220, 250, 260), and wherein the control part determines whether a leakage detection time t of the refrigerant exceeds a first reference time t1 when the leakage of the refrigerant is detected, when the leakage detection time t exceeds the first detection time t1, the control part controls that the first valve is blocked, and when the leakage of the refrigerant continues for a second time t2 after the first valve is blocked, the control part controls that the second valve is blocked.