An electronic device is provided. The electronic device includes a housing including a front surface, a rear surface opposite to the front surface, and a space between the front surface and the rear surface, a display located inside the housing and viewed through the front surface of the housing to the outside of the electronic device, a support member supporting the display by protruding from the side surface toward the inside of the housing, an optical sensor including a light emitting unit and a light receiving unit wherein the optical sensor is located on a rear surface of the display and overlaps at least one area of the display when viewed from top of the front surface; and a partition wall member formed of an elastic material wherein the partition wall member is located between the display and the optical sensor, and at least a part region of the partition wall member is located between the light emitting unit and the light receiving unit to separate the light emitting unit and the light receiving unit.