PURPOSE: To provide a compound detecting method for organic compound capable of highly sensitive microanalysis and an inexpensive detecting device for organic compound having a simple structure.

CONSTITUTION: An elute from the column 6 of a liquid chromatography 1 is dropped onto a water-repellent thin film 18. An infrared ray is emitted to the sample 12 of an organic material concentrated and condensed on the thin film 18, and the reflected infrared ray obtained at that time is detected. The degree of the absorption is measured, whereby the presence of the organic material and its concentration are detected.