Abstract: In an electronic device comprising a first substrate having at least one first electronic circuit element thereon, a second substrate having at least one second electronic circuit element thereon, a substrate connector through which the first and second electronic circuit elements are connected electrically to each other, and an electrically grounded chassis receiving the first and second substrates, the first substrate has thereon a first electromagnetic shielding plate including an electrically conductive material, the second substrate has thereon a second electromagnetic shielding plate including the electrically conductive material, the first and second electromagnetic shielding plates are electrically connected to the chassis, and a wire length between a wire length limited electronic circuit element on the first substrate and another of the electronic circuit elements on the second substrate is limited for ensuring a high speed responsive operation therebetween.