A refrigerator comprising: a cabinet in which an upper storage space and a lower storage space are defined; a door part opening and closing the lower storage space through insertion/withdrawal thereof; and a drawer part connected to the door part so as to be inserted into and withdrawn from the lower storage space and providing an accommodation space, characterized in that the refrigerator comprises: a support member which is provided in the drawer part and on which a food or a container can be seated; a draw-out rail connecting the drawer part to an inner wall surface of the storage space and extending in a multistage to insert and withdraw the door part and the drawer part; a plurality of outer side plates are disposed on each of both left and right surfaces of the outside of the drawer part to define an outer appearance of the drawer part and faces each of the both side surfaces of the drawer part; an elevation device provided on each of both side surfaces of the drawer part and connected to both side ends of the support member to elevate the support member; and a rail mounting part, on which the draw-out rail is mounted is disposed on a lower end of an outer surface of the drawer part, wherein a drawer flange having a predetermined width is disposed on an upper end of each of both the side surfaces of the drawer part, and the draw-out rail and the elevation device are disposed inside a space defined below the drawer flange and between the outside of drawer part and the outer side plate and the draw-out rail and the elevation device are covered by the outer side plate, wherein the rail mounting part comprises: a top surface portion that extends outward from the outer surface of the drawer part and that is configured to face a top surface of the at least one draw-out rail; and a side surface portion that extends downward from an outer end of the top surface portion and that defines an accommodation space configured to receive the at least one draw-out rail. a support member which is provided in the drawer part and on which a food or a container can be seated; a draw-out rail connecting the drawer part to an inner wall surface of the storage space and extending in a multistage to insert and withdraw the door part and the drawer part; a plurality of outer side plates are disposed on each of both left and right surfaces of the outside of the drawer part to define an outer appearance of the drawer part and faces each of the both side surfaces of the drawer part; an elevation device provided on each of both side surfaces of the drawer part and connected to both side ends of the support member to elevate the support member; and a rail mounting part, on which the draw-out rail is mounted is disposed on a lower end of an outer surface of the drawer part, wherein a drawer flange having a predetermined width is disposed on an upper end of each of both the side surfaces of the drawer part, and the draw-out rail and the elevation device are disposed inside a space defined below the drawer flange and between the outside of drawer part and the outer side plate and the draw-out rail and the elevation device are covered by the outer side plate, wherein the rail mounting part comprises: a top surface portion that extends outward from the outer surface of the drawer part and that is configured to face a top surface of the at least one draw-out rail; and a side surface portion that extends downward from an outer end of the top surface portion and that defines an accommodation space configured to receive the at least one draw-out rail. a top surface portion that extends outward from the outer surface of the drawer part and that is configured to face a top surface of the at least one draw-out rail; and a side surface portion that extends downward from an outer end of the top surface portion and that defines an accommodation space configured to receive the at least one draw-out rail.