We have been using the Tokyo EBIT to study a wide range of electron ion interactions and to measure the energies of transitions in highly charged ions. Transition energies were investigated using visible and X-ray spectroscopy. The two electron contribution to the ground state energy of Helium-like Krypton was measured using absorption-edge spectroscopy. Dielectronic recombination processes were measured by mapping the yield of X-rays as a function of electron energy whilst the time dependence of the evolution of charge states was measured, towards the determination of ionization cross-sections. A brief review of these activities is given.