An electronic device according to the present invention comprises a main body including a pair of body chassis, a pair of cover panels disposed to cover the front face and the back face of the main body, a switch unit disposed on the side part of the main body, an operation button which is held between the pair of cover panels and has a pusher projecting therefrom, a housing recess which is formed on at least one of the body chassis and recessed on a joint surface with the other body chassis to form a housing chamber for the switch unit, a through hole penetrating the one body chassis from the side face toward the housing recess, and a bag-like waterproof packing member which is attached to the through hole and recessed toward the switch unit to house the pusher of the operation button. The pusher of the operation button passes through the through hole toward the switch unit, and the end of the waterproof packing member is pressed against the switch unit to fixedly hold the switch unit inside the housing recess.