The emission line objects such as planetary nebulae, symbiotics, gaseous nebulae, HII regions, novae, supernovae, SNRs, nearby spiral galaxies, dIrr, dE, and nearby active galactic nuclei, would be goldmines for us to dig with the 1.8m bohyunsan optical (BOAO) telescope. We discussed the importance of strategically important diagnostic lines and atomic constant calculation for a study of Galactic and extragalactic emission objects. The scientific background on a spectrometer development history is briefly presented and spectroscopic research areas other than the emission objects are also summarized.