This chapter contains sections titled: Introduction Lasers for MALDI-MS Fragmentation of MALDI Ions MALDI at Elevated Pressure Tandem Mass Spectrometry of MALDI Ions Mass Analyzers Axial TOF Mass Spectrometers Reflectron TOF Mass Spectrometers Tandem TOF Mass Spectrometers Orthogonal TOF Mass Analyzers Tandem Mass Spectrometry in oTOF Mass Analyzers Ion Detectors and Data Processing in MALDI TOF analyzers Fourier Transform Ion Cyclotron Resonance Mass Spectrometers Tandem Mass Spectrometry on FTICR mass Spectrometers Quadrupole Ion Trap Mass Spectrometers RF-Only Ion Guides and LIT Mass Spectrometers Tandem Mass Spectrometry on QIT Mass Spectrometers Hybrid Mass Spectrometers Quadrupole TOF Mass Spectrometers Quadrupole FT Mass Spectrometers QIT-TOF Mass Spectrometers Orbitrap Future Directions References