NOVELTY - Preparation of nanostructured metal oxide or -chalcogenide using chemical bath deposition on a substrate, preferably in the form of nanorods or nanoplates, comprises adding a soluble metal precursor and basic solution as component of bath solution in a vessel, in which a substrate is added and stirring the bath solution during the deposition, where the temperature of the substrate and solution is separately adjusted to a constant and the temperature of the substrate is higher than the temperature of the solution.    USE - The nanostructured metal oxide or -chalcogenide is useful: in optoelectronic devices such as light-emitting diodes, lasers and photodetectors; as electrodes in solar cells; and as support material for catalysis and photocatalysis, preferably with selective function.    ADVANTAGE - The process is a single-step procedure and uses low-cost chemical bath deposition, which ensures the efficient use of raw materials. The process provides nanostructured metal oxides or -chalcogenide with good crystallinity and preferred orientation.    DETAILED DESCRIPTION - Preparation of nanostructured metal oxide or -chalcogenide using chemical bath deposition on a substrate, preferably in the form of nanorods or nanoplates, comprises adding a soluble metal precursor and basic solution as component of bath solution in a vessel, in which a substrate is added and stirring the bath solution during the deposition, where: the temperature of the substrate and solution is separately adjusted to a constant; the temperature of the substrate is higher than the temperature of the solution; and the reaction of components and the deposition of nanostructured end product on the substrate are carried out only in a transparent bath solution. An INDEPENDENT CLAIM is included for a device for the preparation of the nanostructured metal oxide or -chalcogenide comprising a double jacket reactor equipped with a tool for heating the reactor, the bath solution consisting of metallic precursor and basic solution, which is located in the reactor, a substrate with a tool for heating the substrate, where the substrate temperature is higher than the temperature of the solution, and a tool for stirring the solution.