PURPOSE: To achieve a higher working efficiency for a measuring equipment by making the setting and releasing of a gate time selectable at the counting of radiation detection signal to enable the measurement of the dose rate and exposure level with one apparatus.

CONSTITUTION: When dose rate mode is selected with a switch 3, counting contents of a display control circuit 11 is cleared by a reset signal from a generation circuit 14 and each time the gate time selected with a switch 4 passes, the circuit 11 is latched and reset repeatedly. Under such a condition, when a body case 1 is placed in the radiation area, a counting signal proportional to the number of radiation particles incident is outputted, divided 10 in the frequency at a specified ratio, integrated with the circuit 11 and applied to a liquid crystal panel 2 through a driving circuit 12 to display the dose rate. When exposure level meter mode is selected with the switch 3, after the circuit 11 is reset, radiation particles to be exposed during work caught with a counting tube 6 and displayed as exposure dose on a panel 2 via the circuit 11.