Proteomics has been one of the most challenging projects for biological and analytical chemists for many years. Different fractionation, separation, purification and detection techniques that possess appropriate resolution to separate a large number of proteins, as well as being sensitive and fast enough for high throughput protein analysis by combining gel electrophoresis and mass spectrometry were described in that book. Several useful devices for protein/peptide separation based on OFFGEL and Ultra Narrow gel electrophoresis, as well as new ambient ionization technique called ElectroStatic Spray Ionization (ESTASI) mass spectrometry will be presented and discussed in that work.