The present invention relates to a charged-particle detecting apparatus having a structure which enables adjustment of a potential distribution so as to stably maintain flight loci of charged particles without depending on a change in a voltage-applied state. The charged-particle detecting apparatus comprises a first electrode, an MCP, a second electrode, a third electrode that functions as an anode, and a rear cover arranged in order along a predetermined reference axis. The third electrode is arranged on the opposite side of the MCP with respect to the second electrode, and is electrically connected to an output signal part via a capacitor. In particular, the first electrode is arranged so as to become a part of the outer surface of the charged-particle detecting apparatus, and components positioned between the first electrode and the rear cover have contours with section sizes equal to or smaller than that of the contour of the first electrode when viewed from the first electrode side toward the rear cover.