A housing of an electronic device , a portion of the housing being ceramic, the housing comprising: a first surface facing a first direction; a second surface facing a second direction opposite to the first direction; and a third surface surrounding a space between the first surface and the second surface, wherein the third surface includes: a plurality of corner areas ; and a plurality of plane areas connecting the corner areas to each other, wherein a plane area of the plurality of plane areas includes: a recess area on the housing recessed inward along a peripheral portion of the recess area, and wherein an opening is formed in the recess area passing through an inner part and an outer part of the third surface, the opening further including a first part formed in an inner surface of the housing and a second part formed in a recess area in an outer surface of the housing and connected with the first part, and wherein a diameter of the second part is greater than a diameter of the first part and, wherein a roughness of an inner surface of the second part is uniform and different to a roughness of an inner surface of the first part . a first surface facing a first direction; a second surface facing a second direction opposite to the first direction; and a third surface surrounding a space between the first surface and the second surface, wherein the third surface includes: a plurality of corner areas ; and a plurality of plane areas connecting the corner areas to each other, wherein a plane area of the plurality of plane areas includes: a recess area on the housing recessed inward along a peripheral portion of the recess area, and wherein an opening is formed in the recess area passing through an inner part and an outer part of the third surface, the opening further including a first part formed in an inner surface of the housing and a second part formed in a recess area in an outer surface of the housing and connected with the first part, and wherein a diameter of the second part is greater than a diameter of the first part and, wherein a roughness of an inner surface of the second part is uniform and different to a roughness of an inner surface of the first part . a plurality of corner areas ; and a plurality of plane areas connecting the corner areas to each other, wherein a plane area of the plurality of plane areas includes: a recess area on the housing recessed inward along a peripheral portion of the recess area, and wherein an opening is formed in the recess area passing through an inner part and an outer part of the third surface, the opening further including a first part formed in an inner surface of the housing and a second part formed in a recess area in an outer surface of the housing and connected with the first part, and wherein a diameter of the second part is greater than a diameter of the first part and, wherein a roughness of an inner surface of the second part is uniform and different to a roughness of an inner surface of the first part . a recess area on the housing recessed inward along a peripheral portion of the recess area, and wherein an opening is formed in the recess area passing through an inner part and an outer part of the third surface, the opening further including a first part formed in an inner surface of the housing and a second part formed in a recess area in an outer surface of the housing and connected with the first part, and wherein a diameter of the second part is greater than a diameter of the first part and, wherein a roughness of an inner surface of the second part is uniform and different to a roughness of an inner surface of the first part . <EOS>