A refrigerator comprising a cabinet that has a storage space formed therein, a grill pan that defines a rear wall surface of the storage space, a purification device that is mounted on the grill pan to suck and purify air within the storage space; a duct unit comprising a cold air passage that is formed on a rear side of the grill pan to guide cold air of an evaporator to the storage space and a purification passage that guides the air purified by the purification device to the storage space again, wherein the duct unit comprises: a purification duct that is arranged at a center of the grill pan to define the purification passage; and cold air ducts that are arranged on opposite sides of the purification duct to define the cold air passage, wherein the purification device is located at an upper end of the grill pan to purify the air within the storage space, and wherein a cold air fan assembly that blows the cold air of the evaporator is located at a lower end of the grill pan to discharge the cold air from a lower side to an upper side thereof, characterized in that centers of the grill pan and the duct unit are recessed in a shape corresponding to a mounting member holder such that the mounting member holder for mounting a shelf is mounted thereon. a cabinet that has a storage space formed therein, a grill pan that defines a rear wall surface of the storage space, a purification device that is mounted on the grill pan to suck and purify air within the storage space; a duct unit comprising a cold air passage that is formed on a rear side of the grill pan to guide cold air of an evaporator to the storage space and a purification passage that guides the air purified by the purification device to the storage space again, wherein the duct unit comprises: a purification duct that is arranged at a center of the grill pan to define the purification passage; and cold air ducts that are arranged on opposite sides of the purification duct to define the cold air passage, wherein the purification device is located at an upper end of the grill pan to purify the air within the storage space, and wherein a cold air fan assembly that blows the cold air of the evaporator is located at a lower end of the grill pan to discharge the cold air from a lower side to an upper side thereof, characterized in that centers of the grill pan and the duct unit are recessed in a shape corresponding to a mounting member holder such that the mounting member holder for mounting a shelf is mounted thereon. a purification duct that is arranged at a center of the grill pan to define the purification passage; and cold air ducts that are arranged on opposite sides of the purification duct to define the cold air passage, wherein the purification device is located at an upper end of the grill pan to purify the air within the storage space, and wherein a cold air fan assembly that blows the cold air of the evaporator is located at a lower end of the grill pan to discharge the cold air from a lower side to an upper side thereof, characterized in that centers of the grill pan and the duct unit are recessed in a shape corresponding to a mounting member holder such that the mounting member holder for mounting a shelf is mounted thereon.