The so-called "green phases" of composition LnzBaCuO 5 (Ln = lanthanide) are one of the greatest impurities generated during the solid-state synthesis of the new high-T~ superconducting ceramic materials related to YBa2Cu3OT_ x (see, for example [1, 2]). In a recent paper we have analysed the vibrationalspectroscopic behaviour of the complete series of "green phases" [3]. As a continuation of this study, and in order to broaden our knowledge on the physicochemical properties of this type of phase, we have now investigated the electronic spectrum of YzBaCuOs, which can be considered a prototype for the whole series. This study is also very interesting within the context of the electronic spectroscopy of oxidic materials, due to the scarce information on MO 5 systems and MO 6 systems [4-7].