To provide a personal dosimeter in which a shield bag for housing a substrate and a cap having a shield property are electrically connected and airtightness between a body and a cap is enhanced.

An outer surface of a holder 36 is formed with an annular groove 58, and a ring-shaped band member 30 is fitted therein. The band member 30 has conductivity and elasticity. An end part 28A of a shield bag 28 housing a substrate is fitted between the holder 36 and the band member 30. When a cap is mounted, a shield property is exhibited by the band member 30, and at the same time, the shield bag 28 and the cap are electrically connected via the band member. Terminal plates 62 having bent forms are connected to an electrode of a battery, and at that time, an inner surface of the shield bag 28 is pressed by bent ends of the terminal plates 62.