An electronic device according to one embodiment of the present disclosure may include: a housing; an optical element unit which may be configured to emit light toward a user's body, receive light reflected from the user's body, and convert the received light into a first signal; an IC element which may be configured to convert the first signal provided from the optical element unit into a second signal, and provide the second signal to a main circuit board disposed in the housing; a first circuit board that may be disposed between the optical element unit and the IC element and may be electrically connected to the optical element unit and the IC element; and a second circuit board that may include at least one first opening in which the IC element is mounted. The housing may include at least one transparent region such that the light generated by the optical element unit is transmitted through the transparent region to an exterior of the housing.