An air conditioner, comprising: a compressor (110, 112) that compresses a refrigerant; a condenser that condenses the refrigerant compressed in the compressor (110, 112); an expansion device (153, 173) that decompresses the refrigerant condensed in the condenser; an evaporator that evaporates the refrigerant decompressed in the expansion device (153, 173); and a refrigerant storage that bypasses at least a portion of the refrigerant condensed in the condenser to store the bypassed refrigerant therein, wherein the refrigerant storage includes: a first storage that stores the bypassed refrigerant; and a second storage into which the refrigerant passing through the evaporator is introduced, wherein the second storage discharges a gaseous refrigerant of the introduced refrigerant to the compressor (110, 112), characterized in that: the first storage is provided above the second storage to supply the refrigerant stored therein into the second storage, and the air conditioner further includes: a receiver outlet tube that extends from the first storage to the second storage downward to guide a flow of the refrigerant stored in the first storage into the second storage using a natural gradient or gravity; a liquid discharge port provided in the first storage and to which a first side of the receiver outlet tube is coupled; a liquid inflow port provided in the second storage and to which a second side of the receiver outlet tube is coupled; and a receiver outlet valve installed on the receiver outlet tube to adjust an amount of refrigerant discharged from the first storage. a compressor (110, 112) that compresses a refrigerant; a condenser that condenses the refrigerant compressed in the compressor (110, 112); an expansion device (153, 173) that decompresses the refrigerant condensed in the condenser; an evaporator that evaporates the refrigerant decompressed in the expansion device (153, 173); and a refrigerant storage that bypasses at least a portion of the refrigerant condensed in the condenser to store the bypassed refrigerant therein, wherein the refrigerant storage includes: a first storage that stores the bypassed refrigerant; and a second storage into which the refrigerant passing through the evaporator is introduced, wherein the second storage discharges a gaseous refrigerant of the introduced refrigerant to the compressor (110, 112), a first storage that stores the bypassed refrigerant; and a second storage into which the refrigerant passing through the evaporator is introduced, wherein the second storage discharges a gaseous refrigerant of the introduced refrigerant to the compressor (110, 112), characterized in that: the first storage is provided above the second storage to supply the refrigerant stored therein into the second storage, and the air conditioner further includes: a receiver outlet tube that extends from the first storage to the second storage downward to guide a flow of the refrigerant stored in the first storage into the second storage using a natural gradient or gravity; a liquid discharge port provided in the first storage and to which a first side of the receiver outlet tube is coupled; a liquid inflow port provided in the second storage and to which a second side of the receiver outlet tube is coupled; and a receiver outlet valve installed on the receiver outlet tube to adjust an amount of refrigerant discharged from the first storage. the first storage is provided above the second storage to supply the refrigerant stored therein into the second storage, and the air conditioner further includes: a receiver outlet tube that extends from the first storage to the second storage downward to guide a flow of the refrigerant stored in the first storage into the second storage using a natural gradient or gravity; a liquid discharge port provided in the first storage and to which a first side of the receiver outlet tube is coupled; a liquid inflow port provided in the second storage and to which a second side of the receiver outlet tube is coupled; and a receiver outlet valve installed on the receiver outlet tube to adjust an amount of refrigerant discharged from the first storage. a receiver outlet tube that extends from the first storage to the second storage downward to guide a flow of the refrigerant stored in the first storage into the second storage using a natural gradient or gravity; a liquid discharge port provided in the first storage and to which a first side of the receiver outlet tube is coupled; a liquid inflow port provided in the second storage and to which a second side of the receiver outlet tube is coupled; and a receiver outlet valve installed on the receiver outlet tube to adjust an amount of refrigerant discharged from the first storage.