A refrigerator comprising: a cabinet having an opened front surface, the cabinet providing a first storage region in which a plurality of shelves are vertically disposed; a first door having a second storage region in which a plurality of shelves are vertically disposed and an opening enabling a user to access to the second storage region, the first door being rotatably connected to the cabinet to open or close the first storage region; a second door rotatably connected to the first door so that the second door rotates to open the opening in the same direction as the rotation direction of the first door for opening the first storage region; a first connection member connecting the cabinet to the first door; a second connection member connecting the first door to the second door; an auxiliary shelf connected to a side of the opening to rotate in a direction crossing the rotation direction of the second door when the second door is opened or closed; characterized by a guide roller disposed on a side of an edge of the auxiliary shelf; and a shelf guide disposed on a back surface of the second door to guide the opening/closing operation of the auxiliary shelf while being maintained in a contact state with the guide roller within a predetermined section; wherein the shelf guide comprises: a guide cover mounted on the back surface of the second door; a guide lever having an upper end rotatably mounted on the guide cover, the guide lever contacting the guide roller when the second door is opened or closed; and a lever spring supporting the guide lever at a rear side of the guide lever, the lever spring providing an elastic force in a direction in which the guide lever protrudes from the guide cover. a cabinet having an opened front surface, the cabinet providing a first storage region in which a plurality of shelves are vertically disposed; a first door having a second storage region in which a plurality of shelves are vertically disposed and an opening enabling a user to access to the second storage region, the first door being rotatably connected to the cabinet to open or close the first storage region; a second door rotatably connected to the first door so that the second door rotates to open the opening in the same direction as the rotation direction of the first door for opening the first storage region; a first connection member connecting the cabinet to the first door; a second connection member connecting the first door to the second door; an auxiliary shelf connected to a side of the opening to rotate in a direction crossing the rotation direction of the second door when the second door is opened or closed; characterized by a guide roller disposed on a side of an edge of the auxiliary shelf; and a shelf guide disposed on a back surface of the second door to guide the opening/closing operation of the auxiliary shelf while being maintained in a contact state with the guide roller within a predetermined section; wherein the shelf guide comprises: a guide cover mounted on the back surface of the second door; a guide lever having an upper end rotatably mounted on the guide cover, the guide lever contacting the guide roller when the second door is opened or closed; and a lever spring supporting the guide lever at a rear side of the guide lever, the lever spring providing an elastic force in a direction in which the guide lever protrudes from the guide cover. a guide cover mounted on the back surface of the second door; a guide lever having an upper end rotatably mounted on the guide cover, the guide lever contacting the guide roller when the second door is opened or closed; and a lever spring supporting the guide lever at a rear side of the guide lever, the lever spring providing an elastic force in a direction in which the guide lever protrudes from the guide cover.