This paper presents a formal approach to proving temporal reachability properties, expressed in CTL, on B systems. We are particularly interested in demonstrating that a system can reach a given state by executing a sequence of actions (or operation calls) called a path. Starting with a path, the proposed approach consists in calculating the proof obligations to discharge in order to prove that the path allows the system to evolve in order to verify the desired property. Since these proof obligations are expressed as first logic formulas without any temporal operator, they can be discharged using the prover of AtelierB. Our proposal is illustrated through a case study