An electronic device having a slide cover slidably attached in an openable/closable manner to a device case, and conceals a recording paper ejection opening in the device case; a waterproof gasket provided on either one of the slide cover and the device case in a part positioned in periphery of the recording paper ejection opening, and arranged between the slide cover and the device case surrounding the recording paper ejection opening, when the slide cover conceals the recording paper ejection opening; and a guide member which does not come in contact with the waterproof gasket on another side of the slide cover and the device case with which the waterproof gasket meets face to face during a sliding motion of the slide cover, and the waterproof gasket presses on both sides between the slide cover and the device case when the sliding motion is completed.