| CPC G01N 27/624 (2013.01) | 13 Claims |

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1. A detector device comprising:
a pair of filter electrodes that are disposed opposite each other;
a collector electrode collecting charged particles that pass through a space between the pair of filter electrodes; and
a detection circuit connected to the collector electrode and detecting an amount of the charged particles that are collected, wherein
the collector electrode includes
an upper electrode layer having a collection surface that receives the charged particles,
a lower electrode layer that is disposed opposite a surface of the upper electrode layer that is an opposite surface from the collection surface, and
an insulation layer having an insulation property and disposed between the upper electrode layer and the lower electrode layer, and
the detection circuit is configured to be connected to one of the upper electrode layer and the lower electrode layer.
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