RADIATION MEASUREMENT DEVICE

A radiation measurement device having a radiation detector, a measurement instrument provided with a signal conversion unit for carrying out signal conversion on a detection current signal output from the radiation detector, and a signal input line for supplying the detection current signal output from the radiation detector to the signal conversion unit, wherein if a test mode is selected, a test current signal is superposed on the detection current signal and supplied to the signal conversion unit through the closing of contacts and the connection of a constant-voltage source and the signal input line, and if a normal mode is selected, the constant-voltage source is connected to a point having the same potential as the signal input line and the generation of a potential difference between the contacts is prevented through the opening of the contacts and the disconnection of the constant-voltage source and signal input line.