A probe device including a cantilever. Such electrode active materials include those of the formula:AaMnbMIcMIIdMIIIePO4 wherein A is selected from the group consisting of Li, Na, K, and mixtures thereof, and 0<a\u22661; 0<b\u22661; MI is a metal ion in the +3 oxidation state, and 0<c<0. The instruments may include a chisel. The dielectric substrate includes a body fluid side elevated portion generally raised above the conductive ferrule. Accordingly, even if the user may inadvertently operate the image forming apparatus while not operating the lockingreleasing unit so that the transferring unit and the photoconductive unit are not fixed to each other, the image forming apparatus notifies the user.