Abstract: We wish to introduce here a mass spectral library search system establi-shed on a personal microcomputer. This system allows a user to create his ownspectral library containing a specific class of compound. It allows him to ap-pend and edit spectral data and descriptive information, as well as the gene-ration and examination of keywords which are used in library searching. Fi-nally, users can key in spectral data of unknown samples and search for ma-tching compounds in the library. The Hardware configuration of the systemis extremely simple and basically consists of a CBM/PET 2001 microcomputerconnected to a PET-2040 5.5 inch floppy disk subsystem. The spectral libraryincluding data and descriptive information is stored in one diskette, eachspectrum is represented as an individual file. All the programs for the mana-gement, maintenance and search of the data base together with the variousindex files are stored in another diskette. A modular approach is taken inprogramming the system and a two steps search technique is utilized in thesearch process.