A mobile electronic device comprising: a display panel comprising a plurality of layers including a front panel comprising a plurality of pixels, the plurality of layers further including a metal sheet layer including a first opening defined therein; a housing disposed below the front panel and having a second opening, and an upper surface of the housing being attached to a rear surface of the display panel; a biometric sensor disposed below the front panel via the housing so that an upper surface of the biometric sensor is exposed through the second opening of the housing, and faces a rear surface of the front panel through at least a portion of the second opening of the housing and the first opening in the metal sheet layer; and a first printed circuit board disposed below the biometric sensor and electrically coupled to the biometric sensor, the biometric sensor being attached to an upper surface of the first printed circuit board by a first adhesive member, wherein a lower surface of the housing is attached to the upper surface of the first printed circuit board by a second adhesive member, wherein the housing is configured to position the biometric sensor such that the upper surface of the biometric sensor is spaced apart from the rear surface of the front panel via an unoccupied space formed by at least the portion of the second opening of the housing in addition to the first opening of the metal sheet layer, wherein the biometric sensor includes an image sensor and an optical layer disposed on at least a partial area of the image sensor, and wherein an upper surface of the optical layer is closer to the printed circuit board than an area of the rear surface of the display panel that attaches to the upper surface of the housing. a display panel comprising a plurality of layers including a front panel comprising a plurality of pixels, the plurality of layers further including a metal sheet layer including a first opening defined therein; a housing disposed below the front panel and having a second opening, and an upper surface of the housing being attached to a rear surface of the display panel; a biometric sensor disposed below the front panel via the housing so that an upper surface of the biometric sensor is exposed through the second opening of the housing, and faces a rear surface of the front panel through at least a portion of the second opening of the housing and the first opening in the metal sheet layer; and a first printed circuit board disposed below the biometric sensor and electrically coupled to the biometric sensor, the biometric sensor being attached to an upper surface of the first printed circuit board by a first adhesive member, wherein a lower surface of the housing is attached to the upper surface of the first printed circuit board by a second adhesive member, wherein the housing is configured to position the biometric sensor such that the upper surface of the biometric sensor is spaced apart from the rear surface of the front panel via an unoccupied space formed by at least the portion of the second opening of the housing in addition to the first opening of the metal sheet layer, wherein the biometric sensor includes an image sensor and an optical layer disposed on at least a partial area of the image sensor, and wherein an upper surface of the optical layer is closer to the printed circuit board than an area of the rear surface of the display panel that attaches to the upper surface of the housing.