A method of controlling a refrigerator comprising a refrigerator compartment and a freezer compartment, a first evaporator is disposed at a side of the refrigerator compartment, and a second evaporator disposed at a side of the freezer compartment, a compressor having a second compressor disposed at a low pressure side and a first compressor for further compressing refrigerant compressed at the second compressor, wherein an outlet side refrigerant pipe of a second evaporator extends to an inlet of the second compressor such that the refrigerant passed through the second evaporator is introduced into the second compressor, wherein an outlet side refrigerant pipe of a first evaporator is connected to an outlet side of refrigerant pipe of the second compressor such that the refrigerant passed through the first evaporator joins the refrigerant compressed at the second compressor and is introduced into the first compressor, wherein the refrigerant compressed at the first compressor is introduced into a condenser, wherein the refrigerator further comprises: a first refrigerant passage configured to guide introduction of the refrigerant into the first evaporator, the first refrigerant passage having a first expansion device installed; a third refrigerant passage configured to guide introduction of the refrigerant into the first evaporator, the third refrigerant passage having a third expansion device installed; a second refrigerant passage configured to guide introduction of the refrigerant into the second evaporator, the second refrigerant passage having a second expansion device installed; a storage temperature sensor (210, 220) adapted to sense an inner temperature of the refrigerator compartment or the freezer compartment; an outer temperature sensor adapted to sense an outer temperature of the refrigerator compartment and the freezer compartment, that is, a temperature of an indoor space in which the refrigerator is installed; a flow adjusting part adapted to adjust amounts of the refrigerant flowing through the first, the second and the third refrigerant passages (101, 105, 103); a memory part in which information about control times of the flow adjusting part is mapped onto information sensed at the storage temperature sensor (210, 220) and the outer temperature sensor and is stored; and a control part adapted to control the flow adjusting part to supply the refrigerant to the first and second evaporators (150, 160), based on the mapped information stored in the memory part, the method comprises the steps of: driving a refrigerating cycle including the first and the second evaporator (150, 160) by activating the first and second compressor (111, 115); simultaneously supplying cold air to the refrigerator compartment and the freezer compartment by supplying refrigerant to the first and second evaporators (150, 160) according to the driving of the refrigerating cycle; when the first and second evaporators and are simultaneously operated, preventing the refrigerant from being insufficiently introduced into the first evaporator by operating the flow adjusting part and thereby opening the first, second and third refrigerant passages (101, 103, 105) for a first set time, to allow a flow rate of the refrigerant supplied to the first evaporator to increase; preventing the refrigerant from being insufficiently introduced into the second evaporator by operating the flow adjusting part and thereby opening the first and second refrigerant passages (101, 103) and closing the third refrigerant passage for a second time to allow a flow rate of the refrigerant supplied to the second evaporator to increase. driving a refrigerating cycle including the first and the second evaporator (150, 160) by activating the first and second compressor (111, 115); simultaneously supplying cold air to the refrigerator compartment and the freezer compartment by supplying refrigerant to the first and second evaporators (150, 160) according to the driving of the refrigerating cycle; when the first and second evaporators and are simultaneously operated, preventing the refrigerant from being insufficiently introduced into the first evaporator by operating the flow adjusting part and thereby opening the first, second and third refrigerant passages (101, 103, 105) for a first set time, to allow a flow rate of the refrigerant supplied to the first evaporator to increase; preventing the refrigerant from being insufficiently introduced into the second evaporator by operating the flow adjusting part and thereby opening the first and second refrigerant passages (101, 103) and closing the third refrigerant passage for a second time to allow a flow rate of the refrigerant supplied to the second evaporator to increase.