A radiation meter (1) is provided with: a radiation sensor (10) which generates detection signals in the case where radiation is detected; a first counter (15) which counts the detection signals; an oscillator (16) which generates periodic signals with a predetermined period; an AND circuit (17) which outputs logical product of the detection signals and the periodic signals; a second counter (18) which counts output signals of the AND circuit (17); and an indicator (23), which indicates a count value obtained from the first counter (15) in the case where a count value obtained from the second counter (18) is less than a predetermined value, and indicates a value different from an actual count value obtained from the first counter (15) in the case where a count value obtained from the second counter (18) is equal to or more than the predetermined value.
