Patent ID: 7189956

Claim:
A photomultiplier comprising: a conductive first side tube; a conductive second side tube; a photoelectric surface disposed inside the sealed container formed of the first side tube and the second side tube and put in a vacuum state, and converting incident light made incident through a light receiving plate into electrons, which forms an end portion at one side of the sealed container; an electron multiplier unit disposed inside the sealed container and multiplying electrons emitted from the photoelectric surface; an anode disposed inside the sealed container and used for taking out the electrons multiplied by the electron multiplier unit as an output signal; a stem forming an end portion at the other side of the sealed container; and a plurality of stem pins insertedly mounted in the stem and leading to the exterior from inside the sealed container and electrically connected to the anode and the electron multiplier unit, wherein the first side tube surrounds the anode and the electron multiplier unit from the side, and the second side tube is positioned at the stem side of the first side tube and is joined to one end portion of the first side tube and the side surface of the stem, and the stem is joined to the second side tube so as to protrude out towards the first side tube from the second side tube, and the first side tube is joined to the second side tube in a state of being directly capped onto the portion of the stem that protrudes out from the second side tube.