A food storage apparatus, comprising: a first storage room, a second storage room and a third storage room to store food, wherein the third storage room is a cooling chamber configured to be maintained at a temperature range between 3-4°C, the second storage room is a freezing compartment configured to be maintained at a temperature below 0°C and the first storage room is a switching room configured to be maintained at a prescribed temperature which is lower than the temperature of the third storage room and higher than the temperature of the second storage room; a lower frame that the second storage room and the first storage room are mounted on; an upper frame that the third storage room is mounted on; a first cooler that the second storage room and the first storage room share for supplying cold air and; a second cooler provided to the cooling chamber to generate cold air and provided in a rear wall side of the upper frame and can be separated from third storage room by a cover; a partition provided in the lower frame configured to separate the first storage room and the second storage room; and a duct unit provided as a single body and including: a first duct to guide cold air through a first outlet into the first storage room, a second duct to guide cold air through a second outlet into the second storage room, a scroll-type fan housing from which the first duct and the second duct diverge, a guide which forms an intake passage for collecting the cold air from the second storage room, a first inlets for sucking the cold air out of the first storage room, a return duct to guide the cold air sucked via the first inlets to the first cooler; and a first damper that controls a flow of cold air through the first duct, a fan mounted in the scroll-type fan housing that blows cold air into the first and second ducts; wherein the food storage apparatus further comprises: a constructing space for accommodating the first cooler, wherein the constructing space and the first cooler extend over portions between the first storage room and second storage room, wherein the duct unit is assembled in the construction space to block a front side of the constructing space, as the duct unit blocks the constructing space for accommodating the first cooler therein, and the constructing space 120 does not have any cold air passage communicating with the first storage room and second storage room except the cold air flow passages. a first storage room, a second storage room and a third storage room to store food, wherein the third storage room is a cooling chamber configured to be maintained at a temperature range between 3-4°C, the second storage room is a freezing compartment configured to be maintained at a temperature below 0°C and the first storage room is a switching room configured to be maintained at a prescribed temperature which is lower than the temperature of the third storage room and higher than the temperature of the second storage room; a lower frame that the second storage room and the first storage room are mounted on; an upper frame that the third storage room is mounted on; a first cooler that the second storage room and the first storage room share for supplying cold air and; a second cooler provided to the cooling chamber to generate cold air and provided in a rear wall side of the upper frame and can be separated from third storage room by a cover; a partition provided in the lower frame configured to separate the first storage room and the second storage room; and a duct unit provided as a single body and including: a first duct to guide cold air through a first outlet into the first storage room, a second duct to guide cold air through a second outlet into the second storage room, a scroll-type fan housing from which the first duct and the second duct diverge, a guide which forms an intake passage for collecting the cold air from the second storage room, a first inlets for sucking the cold air out of the first storage room, a return duct to guide the cold air sucked via the first inlets to the first cooler; and a first damper that controls a flow of cold air through the first duct, a fan mounted in the scroll-type fan housing that blows cold air into the first and second ducts; wherein the food storage apparatus further comprises: a constructing space for accommodating the first cooler, wherein the constructing space and the first cooler extend over portions between the first storage room and second storage room, wherein the duct unit is assembled in the construction space to block a front side of the constructing space, as the duct unit blocks the constructing space for accommodating the first cooler therein, and the constructing space 120 does not have any cold air passage communicating with the first storage room and second storage room except the cold air flow passages. a constructing space for accommodating the first cooler, wherein the constructing space and the first cooler extend over portions between the first storage room and second storage room, wherein the duct unit is assembled in the construction space to block a front side of the constructing space, as the duct unit blocks the constructing space for accommodating the first cooler therein, and the constructing space 120 does not have any cold air passage communicating with the first storage room and second storage room except the cold air flow passages.