APPARATUS FOR MEASURING TIME-DEVELOPED SPECTRUM

PROBLEM TO BE SOLVED: To provide a time change spectrum-measuring apparatus which can reduce a burden for taking of data and at the same time can be simplified in constitution. SOLUTION: A measuring apparatus 10 has measuring means 12, 14, 16, 18 for sequentially outputting time change interferogram data of a sample, a clock 22 for outputting time information, a temporary memory means 21 for temporarily storing the interferogram data from the measuring means 12, 14, 16, 18 correlatively to the time information of the clock 22, a filter 24 and a main memory means 26 for storing time change interferogram data sent out from the filter 24. During the measurement of an interferogram by the measuring means 12, 14, 16, 18, the filter 24 monitors in real time the time change interferogram data stored in the temporary memory means 21 and, sends out time change interferogram data indicating a large change value from a predetermined threshold value with respect to the interferogram data before a time change.