  Angle resolved photoemission spectroscopy (ARPES) enables direct observation
of the Fermi surface and underlying electronic structure of crystals---the
basic concepts to describe all the electronic properties of solids and to
understand the key electronic interactions involved. The method is the most
effective to study quasi-2D metals, to which the subjects of almost all hot
problems in modern condensed matter physics have happened to belong. This has
forced incredibly the development of the ARPES method which we face now. The
aim of this paper is to introduce to the reader the state-of-the-art ARPES,
reviewing the results of its application to such topical problems as high
temperature superconductivity in cuprates and iron based superconductors, and
electronic ordering in the transition metal dichalcogenides and manganites.
