Optical measurement that is optimum for improving spatial resolution is accomplished
by making it possible to estimate a physical quantity of an object substance to
be measured at any point on a subject. When any position to be evaluated, in an
image shown in a window 1-1, is pointed and selected a mouse pointer
1-4, the value of the concentration or its change of the object substance
at the point is displayed in the display area 1-7 of a window 1-3.
The drawings represents an example in which one position is specified and there
are two object substances to be measured. The value of the concentration or its
change of each object substance to be measured is separately displayed.