WATER QUALITY EVALUATION METHOD AND DEVICE

PROBLEM TO BE SOLVED: To provide a water quality evaluation device and its method for accurately evaluating the water quality of ultra pure water or the like in spite of its relatively simple device structure. SOLUTION: A substrate holding container 11 of this water quality evaluation device 10 is provided with a light projector 30 projecting light toward a substrate W housed in the container 11, a reflective light trap 40 absorbing reflective light from the substrate W, and a scattered light receiver 50 receiving scattered light from the substrate W. The light receiver 50 is equipped with a scattered-light intensity recording/computing unit 52 recording the intensity of the scattered light with time. With test water let run into the container 11, light is projected from the light projector 30 toward the substrate W in the container 11 while the intensity of the scattered light from the substrate W is detected by the light receiver 50, and detected values are recorded with time by the unit 52. COPYRIGHT: (C)2008,JPO&INPIT