A refrigerator comprising: a main body having a front side thereof open; and a door provided to open and close the open front side of the main body, wherein the door includes a door body and a door panel detachably mountable on the door body: wherein the door body includes: a lower door cap; an upper door cap including a front opening formed on a front surface of the upper door cap and a passing opening formed on an upper surface of the upper door cap; a cover forming the front surface of the door body; and chassis (121, 126) forming both side surfaces of the door body; wherein the door panel includes: a panel body including a rear surface facing the cover; an upper trim on the rear surface of the panel body and including an upper trim protrusion formed to protrude rearward; and a lower trim on the rear surface of the panel body; wherein the door further includes a fixed cover positioned on the upper door cap, the upper trim protrusion is inserted into the upper door cap through the front opening of the upper door cap, a portion of the fixed cover is inserted into the upper door cap through the passing opening of the upper door cap and is inserted to an upper trim hol of the upper trim protrusion, and another portion of the fixed cover is provided to correspond to the passing opening of the upper door cap to form a portion of an upper surface of the upper door cap. a main body having a front side thereof open; and a door provided to open and close the open front side of the main body, wherein the door includes a door body and a door panel detachably mountable on the door body: wherein the door body includes: a lower door cap; an upper door cap including a front opening formed on a front surface of the upper door cap and a passing opening formed on an upper surface of the upper door cap; a cover forming the front surface of the door body; and chassis (121, 126) forming both side surfaces of the door body; wherein the door panel includes: a panel body including a rear surface facing the cover; an upper trim on the rear surface of the panel body and including an upper trim protrusion formed to protrude rearward; and a lower trim on the rear surface of the panel body; wherein the door further includes a fixed cover positioned on the upper door cap, the upper trim protrusion is inserted into the upper door cap through the front opening of the upper door cap, a portion of the fixed cover is inserted into the upper door cap through the passing opening of the upper door cap and is inserted to an upper trim hol of the upper trim protrusion, and another portion of the fixed cover is provided to correspond to the passing opening of the upper door cap to form a portion of an upper surface of the upper door cap. wherein the door body includes: a lower door cap; an upper door cap including a front opening formed on a front surface of the upper door cap and a passing opening formed on an upper surface of the upper door cap; a cover forming the front surface of the door body; and chassis (121, 126) forming both side surfaces of the door body; a lower door cap; an upper door cap including a front opening formed on a front surface of the upper door cap and a passing opening formed on an upper surface of the upper door cap; a cover forming the front surface of the door body; and chassis (121, 126) forming both side surfaces of the door body; wherein the door panel includes: a panel body including a rear surface facing the cover; an upper trim on the rear surface of the panel body and including an upper trim protrusion formed to protrude rearward; and a lower trim on the rear surface of the panel body; a panel body including a rear surface facing the cover; an upper trim on the rear surface of the panel body and including an upper trim protrusion formed to protrude rearward; and a lower trim on the rear surface of the panel body; wherein the door further includes a fixed cover positioned on the upper door cap, the upper trim protrusion is inserted into the upper door cap through the front opening of the upper door cap, a portion of the fixed cover is inserted into the upper door cap through the passing opening of the upper door cap and is inserted to an upper trim hol of the upper trim protrusion, and another portion of the fixed cover is provided to correspond to the passing opening of the upper door cap to form a portion of an upper surface of the upper door cap.