This chapter deals with laser microprobe mass analysis (LAMMA), a new microanalytical technique based on laser ion source mass spectrometry that employs high-intensity laser pulses to vaporize and partly ionize small amounts of materials. Most of the microprobe techniques actually in use are still far from satisfying the various analytical requirements needed for particle characterization. In particle analysis, under realistic conditions, there will usually be a predominance of volume evaporation such that in a first approach the local thermodynamic equilibrium (LTE) model and its implications for quantitative analysis might be applicable. In the present state of the LAMMA technique, and with the lack of a theory unifying all physical effects of ion formation, quantitative analysis with LAMMA is difficult particularly if one looks for absolute quantitation. With respect to the special requirements for particle analysis, LAMMA offers a number of advantages if compared with alternative techniques.