It is believed, that shortly after the Big Bang the Universe existed in the state of the Quark Gluon Plasma, where quarks and gluons act as quasi-free particles. During relativistic heavy ion collisions this state of matter can be reproduced. Quantum Chromo-Dynamics (QCD) calculations show possible existence of the critical point and the 1st order phase transition between hadron gas and QGP. The Relativistic Heavy Ion Collider’s (RHIC) program called Beam Energy Scan (BES) was developed for experimental verification of above QCD predictions. Within this program the Solenoidal Tracker At RHIC (STAR) experiment gathered data from gold-gold collisions at √sNN = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4 and 200 GeV. This data are analysed by STAR Collaboration in search for answers to questions concerning the nuclear matter phases, namely: what is the collision energy for the onset of the QGP formation? What is the nature of a phase transition between QGP and hadron gas? Is there a critical point and if yes, where is it situated? In this proceedings a few of the latest STAR results that address these questions are presented.