Electronic apparatus is provided with main body, and inner battery cover and additional module which are attachable and detachable in relation to main body. Battery is stored in opening portion of housing, recessed portion is formed in vertical surface which stands substantially vertically from main surface, and first terminal is formed on inner portion of recessed portion. Connecting surface which comes into contact with vertical surface is formed on additional module, and second terminal which is electrically connected to first terminal is formed on connecting surface. In a state in which additional module is attached to main body, second terminal is positioned on an inner portion of recessed portion and is connected to first terminal, and thus, reliable and firm attachment is performed.