A dosimetry device for charged particle radiation that can be exclusive of cables and connectors between substrates is provided. A plurality of first electrodes are formed on one surface of a printed circuit board, a second electrode substrate having a second electrode opposing each of the plurality of first electrodes through an ionized space is provided, and a signal processing circuit is provided on the other surface opposing the surface of the printed circuit board. The signal processing circuit includes at least one amplifying circuit, a plurality of integrating capacitors corresponding to the amplifying circuit for integrating charge at each corresponding one of the first electrodes, and at least one selector switch that switchably connects each of the integrating capacitors to the amplifying circuit. The printed circuit board may be a multi-layer printed circuit board.