To provide an electronic key with a key contact terminal which is in contact with a key hole contact terminal provided in a key hole when a key is inserted into the key hole, the key contact terminal being protected against damage.

A sliding body 5 is slidably mounted on the surface of the key 3. The sliding body 5 slides between a position covering the key contact terminal 4 arranged on the key 3 and a position exposing the key contact terminal 4, and the sliding body 5 is deflected to be always located at the position covering the key contact terminal 4, by a compression spring 6. Thus, the key contact terminal 4 is covered with the sliding body 5 during nonuse of the electronic key 1 and protected against damage.