PURPOSE: To make it possible to effectively obviate the exposure to redioactive rays, while simplifying the construction and operation, by operating a flow regulating valve at a preset position and by remotely controlling an automatic valve so that a sample may be sampled into a sampling container.

CONSTITUTION: A valve handle 22 of a valve panel 14, which is covered with a radiactive ray shielding palte 20 at a valve operating unit 10, is operated so that a flow regulating valve 16 is adjusted in advance. Then, the chassis 40 of a hood 26, which is covered with a radiocative ray shielding plate in a sampling unit 12 at a partition between the back and the panel 14, is opened, and a sampling container A ia placed below the sampling nozzle 34 of a sampling chamber 24. After the chassis 40 is closed, an automatic valve 32 is opened by a switch operating unit 36 so that the sample is sampled in the container A through the valve 16 and a sample conduit 18. And, the open condition of the valve 32 is displayed in a display lamp 38. After the sampling operation, the valve 32 is colsed, the chassis 40 is opened and the container A is covered. After the outside of the container A and the inside of the hood 26 are rinsed, the container A is taken out.