PURPOSE: To commonly use for both measurements of individual exposure and environmental exposure and to reduce a facility cost by providing dose unit setting means for setting a dose unit in response to a measuring mode.

CONSTITUTION: Before starting an operation of a reader, predetermined number of fluorescent glass dosimeters are charged in a dosimeter insertion unit 31a. In this case, dose unit setting means is executed under control of an operator. That is, when data of the effect that a unit of individual exposure is selected from an operating unit 20 is inputted, a memory for an individual exposure unit is selected. On the other hand, when data of the effect that a unit of environmental exposure is input is selected by the operator, a memory for an environmental exposure unit is similarly selected. Then, a glass element is excited by an ultraviolet ray, generated fluorescence is read, and stored in a memory for storing dose data. The thus stored data is displayed on a display unit 21, and printed by a printer 22.