The separation of organic compounds has been carried out using the method of distillation and recrystallization since the 17th century.1st separation technology innovation (1950s to 1960s). After World War II, the science of separating organic compounds evolved to the use of paper or column chromatography. 2nd separation technology innovation (1960s to 1980s). In the 1960s, thin-layer chromatograpy (TLC) was developed. TLC is a convenient analytical technique for organic compounds. Separation methods for organic compounds using column chromatography and preparative TLC were carried out as practical applications. Gas chromatography (GC) was also introduced in the 1960s. GC is a useful analytical method for a mixture of various volatile organic compounds. Many GC instruments with new kinds of sensors were developed. Gas chromatography of nonbenzenoid organometallic compounds and metal complexes was successfully conducted by the author. 3rd separation technology innovation (1980s to 1990s). In the 1980s, high-performance liquid-chromatography (HPLC) was developed. HPLC analytical methods were useful for various kinds of organic compounds. In the 1990s, LC-MS and LC-NMR instruments were introduced for biomedical products. 4th separation technology innovation (1990s to present). Several new ionization methods for mass-spectrometry (electrospray, matrix-aided lazer desorption ionization, etc) are applied for proteins and biomedical products. Several new separation technologies (supercritical field chromatography, capillary electrophoresis, field-flow fractionization, etc.) are now being developed.