Patent ID: 7821203

Claim:
A photomultiplier comprising a sealed container which includes: a hollow body section extending along a predetermined tube axis; and a faceplate, for transmitting light with a predetermined wavelength, arranged so as to intersect the tube axis, said sealed container accommodating, in its interior, a photocathode, an electron multiplier section which includes at least one set of secondary electron emitting electrodes, and an anode, wherein said faceplate has: a light incidence surface at which the light with the predetermined wavelength arrives; and a light emission surface which opposes said light incidence surface and on which said photocathode is formed, said light emission surface being constituted by: a flat region positioned at a middle of said light emission surface which includes the tube axis; and a curved-surface processed region positioned at a periphery of said flat region which includes edges of said light emission surface, and wherein, in a cross section of said photomultiplier which includes the tube axis and that crosses at least said one set of electrodes, a curve that defines said curved-surface processed region is positioned at the electron multiplier section side, with reference to an intersection of a first straight line on said flat region and a second straight line that is parallel to an inner wall surface of said hollow body section and passes through an edge of said light emission surface.