The present invention relates to a photomultiplier having a fine structure capable of realizing high multiplication efficiency. The photomultiplier comprises a housing whose inside is maintained vacuum, and, on a device mounting surface which is a part of an inner wall surface defining an internal space of the housing, a photocathode serving as a reflection type photocathode, an electron-multiplier section, an anode, and a voltage distributing section are disposed integrally. In particular, the electron-multiplier section is constituted by dynodes at multiple stages cascade-multiplying photoelectrons from the photocathode, and the voltage distributing section, which applies corresponding voltages to the dynodes at the respective stages respectively, is on the same surface together with the electron-multiplier section.