Matrix-assisted laser desorption/ionization time-of-flight mass spectrometers (MALDI-TOFMS) is a powerful tool in the analysis of polymers. High-resolution MALDI-TOFMS facilitates the identification of polymer series by the elemental composition of repeating units and end groups, and allows the calculation of the molecular weight distribution of polymers from the ionic intensity distribution. In actual industrial material analysis, mixtures of polymers with different molecular weight disributions and end groups are analyzed.