This library contains all data mentioned in the paper "Identifying microplastic litter with Laser-Induced Breakdown Spectroscopy (LIBS)". This includes the LIBS data of the reference plastics (PA6, PE, PP, PVC, PET, PC, and PS from the suppliers Vitasheet Group and BAM), the natural materials, and the 45 microparticles. In addition to the LIBS data, the FTIR data of the 45 microparticles are included in the library.