A dual band electrochromic device comprising: - a first transparent conductive substrate where a first electro-optically active electrode is deposited thereon, wherein the first electro-optically active electrode consists of a first nanocrystalline transparent semiconducting layer and at least an electrochromic layer, - a second transparent conductive substrate where a second electro-optically active electrode is deposited thereon, wherein the second electro-optically active electrode consists of a second nanocrystalline transparent semiconducting layer - a temperature dependent ion conductive layer embedded between the first electro-optically active electrode and the second electro-optically active electrode, which comprises a thermo-responsive polymer gel, an ion conductor and an organic plasticizer, wherein - the first electro-optically active electrode is capable of selectively regulating the optical transmittance in the near-infrared spectral range upon the application of an electric bias comprised in a first range of potentials and the optical transmittance in the visible range upon the application of an electric bias comprised in a second range of potentials, - the second electro-optically active electrode can regulate the optical transmittance in the near-infrared range upon the application of an electric bias comprised in a third range of potentials not overlapped neither to the first nor to the second range of potentials of the first electro-optically active electrode, and - the temperature-dependent ion conductive layer can regulate the density of the electric charges flowing between the first and the second electro-optically active electrode according to the temperature variation. - a first transparent conductive substrate where a first electro-optically active electrode is deposited thereon, wherein the first electro-optically active electrode consists of a first nanocrystalline transparent semiconducting layer and at least an electrochromic layer, - a second transparent conductive substrate where a second electro-optically active electrode is deposited thereon, wherein the second electro-optically active electrode consists of a second nanocrystalline transparent semiconducting layer - a temperature dependent ion conductive layer embedded between the first electro-optically active electrode and the second electro-optically active electrode, which comprises a thermo-responsive polymer gel, an ion conductor and an organic plasticizer, wherein - the first electro-optically active electrode is capable of selectively regulating the optical transmittance in the near-infrared spectral range upon the application of an electric bias comprised in a first range of potentials and the optical transmittance in the visible range upon the application of an electric bias comprised in a second range of potentials, - the second electro-optically active electrode can regulate the optical transmittance in the near-infrared range upon the application of an electric bias comprised in a third range of potentials not overlapped neither to the first nor to the second range of potentials of the first electro-optically active electrode, and - the temperature-dependent ion conductive layer can regulate the density of the electric charges flowing between the first and the second electro-optically active electrode according to the temperature variation.