A Cu-BEA sample prepared by conventional ion-exchange was studied by TPR and IR spectroscopy of CO used as a molecular probe. The TPR pattern consists of several peaks at 484, 530, 608, 695, 783 and 988K. On the basis of the FTIR spectra of CO adsorbed at 100K the former four TPR peaks were assigned to reduction of Cu2+ to Cu+, and the last two, to the reduction of Cu+ to Cu0. On the non-reduced sample, Cu2+–CO species and a small amount of Cu+(CO)n carbonyls are observed by IR spectroscopy after CO adsorption. Reduction of the sample by CO at temperatures up to 723K progressively creates Cu+ sites forming different kinds of mono- and polycarbonyl species. The state of copper in the sample is similar after reduction at 723K with either CO or H2: copper is mainly monovalent, although some Cu0 is also detected with the hydrogen-reduced sample. The results evidence that Cu+ ions are stabilized in BEA zeolite, similarly to other monovalent cations, such as Co+ and Ni+.