A battery mount portion includes a recessed portion into which a portion of a battery enters, a coupling terminal provided inside the recessed portion and configured to be electrically coupled to the battery, and a covering portion that covers the coupling terminal and that constitutes a portion of the housing. In a state in which the battery is unmounted, a cover that covers an area in the battery mount portion other than the covering portion is detachably attachable, and a portion where the cover and the housing overlap each other in a depth direction of the recessed portion is located outside a path of a liquid heading towards the coupling terminal after entering the recessed portion through a portion where the cover and the covering portion oppose each other.