Electron multiplier and photoelectron multiplier including same

An electron multiplier comprising:

• a dynode unit configured to cascade-multiply an electron and extracts the electron as an electric signal, the dynode unit including multiple-stage dynodes, an anode which is set to a potential higher than a set potential of a final-stage dynode among the multiple-stage dynodes and captures the electron emitted from the final-stage dynode, and a pair of insulating support members which integrally grip both at least the multiple-stage dynodes and the anode;
• a stem having a first surface and a second surface facing the first surface and holds the dynode unit in a first-surface side space positioned on an opposite side of the second surface to the first surface;
• a coaxial cable having an inner conductor, an insulating material provided on an outer peripheral surface of the inner conductor, and an outer conductor provided on an outer peripheral surface of the insulating material, the coaxial cable having at least one end portion provided in the first-surface side space;
• a conductive member provided in the first-surface side space, the conductive member being provided on the same potential as a potential of the final-stage dynode which directly supplies the multiplied electron to the anode;
• and
• a capacitor provided in the first-surface side space, the capacitor being arranged on a wiring between the conductive member and the outer conductor of the coaxial cable, wherein
• an exposed portion of the inner conductor constituting a part of the one end portion of the coaxial cable and positioned in the first-surface side space in a state of being exposed from end portions of the insulating material and the outer conductor is fixed to a portion of the anode interposed between the pair of insulating support members.