The structural properties of ferroelectric (Ba,Sr)TiO3 films and the electrical parameters of the tunable capacitors on their base were investigated before and after an annealing in oxygen atmosphere at different temperatures. The noticeable impact of the annealing operation on structure properties of the films and microwave parameters of the capacitors was observed at the annealing temperatures higher than the deposition one. The effective suppression of a capacitance slow relaxation effect was observed for all annealing temperatures investigated. (C) 2015 Elsevier B.V. All rights reserved.