PURPOSE: To enable fixing onto an object to be inspected quickly and easily while facilitating removal therefrom as required, by providing an electrode with a fixing means detachable or mountable from/to the object being inspected.

CONSTITUTION: Electrode plates 3 are bonded to both ends of an expanding conductive sheet 1 through conducting resin layers 4, while a lead 6 is connected to the outside of the electrode plate 3 through soldered part. A through hole is provided near almost center of the electrode plate 3, a hook 2 is fitted into the through hole and a recessed section 7 is formed at the bottom of the hook. On the other hand, an expanding object 8 is prepared on the side of the object being inspected. A knuckle 9 of a projected part of the hook 10 is mounted near both ends of the object corresponding to the recessed part 7 of a hook 2. The expanding conductive element can be mounted on or removed from the object being inspected by attaching of the knuckle 9 of the projected part of the hook 10 to or detaching it from the recessed part 7 of the hook 2 on the side of the expanding conductive element.