An electronic device includes: a casing having an opening that houses a connection terminal inside; and a terminal cover that seals the opening such that the connection terminal is not exposed. The terminal cover includes a lid that seals the opening and a fixing part that fixes the terminal cover to the casing. The lid includes a protrusion and a cushion member, the cushion member being mounted around the protrusion and having a surface lower than a surface of the protrusion. The cushion member seals the opening by being in close contact with a member provided around the opening.