An electronic device is provided and includes a display; a first member disposed on a rear surface of the display and including at least one opening; an optical sensor including a light emitting unit and a light receiving unit disposed to emit light to the outside of the display through at least a portion of the at least one opening, and a light receiving unit; and a second member disposed in at least a partial region of the at least one opening and formed to enclose the light emitting unit. At least a part region of the second member is disposed between the light emitting unit and the light receiving unit to separate the light emitting unit and the light receiving unit.