Electronic device

An electronic device, comprising:

• a casing having, at an outer surface thereof, an upper surface and a lower surface that are disposed opposite to each other, and side surfaces for joining peripheral edges of the upper and lower surfaces;
• a terminal port disposed at a side surface of the casing and opened outward of the casing;
• and
• a cap configured to cover the terminal port in an openable and closable manner, wherein
• the cap includes a fitting portion capable of fitting into the terminal port, a pressing surface that is exposed on the side surface of the casing, and a cap-turning support configured to support the cap in the openable and closable manner with respect to the terminal port,
• the pressing surface of the cap is perpendicular to a fitting direction of the cap into the terminal port,
• a portion located directly above and/or below the terminal port in the side surface of the casing constitutes a first protrusion configured to protrude outwardly in an arc-like shape from the side surface of the casing and beyond the pressing surface when the cap is closed,
• a portion on the cap, located above and/or below the pressing surface of the cap, constitutes a second protrusion configured to protrude outwardly in an arc-like shape and in a same direction as that of the first protrusion and beyond the pressing surface when the cap is closed, a major length of the second protrusion extending between an end of the second protrusion disposed relatively nearer to the cap-turning support and an open end of the cap, the major length extending in a direction along the side surfaces that is parallel to the upper and lower surfaces, and
• an outer surface of the first protrusion and an outer surface of the second protrusion are flush such that the outer surface of the first protrusion and the outer surface of the second protrusion constitute a common outer surface in a state where the cap is closed.