[en] Laser spectroscopy studies of antiprotonic helium atoms (p-bar-e^- - He²⁺ ≡ p-barHe⁺) were carried out at the Antiproton Decelerator (AD) of CERN. The experiments used both the direct AD antiproton beam (energy: 5.3 MeV) and the decelerated beam (energy: 20-120 keV). The objectives of the studies are summarized. (R.P.)