Electrons are prevented from being made incident onto an insulation part between dynodes to improve a withstand voltage. The photomultiplier tube 1 is provided with a casing having a glass substrate 40 on which a main surface 40a made with an insulating material is formed, dynodes 31 constituted with a 1st stage to an Nth stage (N denotes an integer of 2 or more) which are arrayed so as to be spaced away sequentially from a first end side to a second end side on the main surface 40a, a photocathode 22 which is installed on the first end side so as to be spaced away from the 1st stage dynode 31a to emit photoelectrons, and an anode part 32 which is installed on the second end side so as to be spaced away from the Nth stage dynode 31j, taking out multiplied electrons as a signal, in which a groove 44, the surface of which is made with an insulating material, is formed between two adjacent dynodes 31 on the main surface 40a of the glass substrate 40, and the 1st stage to the Nth stage dynodes 31 are fixed on raised parts 45 adjacent to the grooves 44 on the glass substrate 40.