A refrigerator includes a cold chamber; a cold chamber door for covering the cold chamber; a freezing chamber; a thermal insulation case on the cold chamber door; an ice-making chamber located on an inner side of the cold chamber door and covered by the thermal insulation case; an ice-making unit installed in the ice-making chamber for making ice using ice-making cold air supplied from the freezing chamber; and a cold air guide structure including: a cold air inlet port for supplying the ice-making cold air into the ice-making chamber; a cold air outlet port for exhausting the ice-making cold air from the ice-making chamber; a cold air supply passage along a wall of the refrigerator to supply the ice-making cold air from the freezing chamber to the cold air inlet port; and a cold air return passage along the wall of the refrigerator to discharge the exhausted ice-making cold air from the cold air outlet port to the freezing chamber.