In order to obtain a dose-rate measuring system that reduces an influence of an electromagnetic induction noise acting around an ionization chamber and a signal converter, a cabinet of the ionization chamber, shields of cables, a cabinet of the signal converter, and a cabinet of a measuring unit are connected in series, and a single-point ground is performed at the measuring unit, and other units except the grounded measuring unit are insulated from the earth, and moreover, a heatproof insulating material having water repellency is coated on a fixed portion of the ionization chamber, whereby the ionization chamber is electrically insulated from a chassis at a fixed side, and the heatproof insulating material having water repellency is coated on a connecting portion of a connector for connecting a cable to another cable, after a waterproof process is performed on the connecting portion by using a bonding tape.