An inspection device for inspecting containers, in particular capsules, each containing a dose of a product in powder or granular form for the preparation of a food product; the device comprising: - a conveyor provided with a plurality of receiving cavities for respective containers and configured to move the receiving cavities along a feed path between a loading station for loading the containers and an unloading station for unloading the containers; - a measuring station located along the feed path between the loading station and the unloading station and configured to inspect each container while the container is being supported and moved by the conveyor, the measuring station comprising a microwave detector provided with a measuring zone through which each container passes, the device further comprising a processing unit configured to receive a measurement signal from the microwave detector and to generate an information item relating to at least one property of the container or of the dose contained therein, preferably density or weight, wherein the conveyor comprises a transporting element defining the feed path and a plurality of supports extending away from the transporting element transversely to the feed path and each having two or more of the receiving cavities, and characterized by each support being rotatable about a swivel axis to adopt at least a first position, where the receiving cavities of the support are disposed in alignment transversely, preferably perpendicularly, to the feed path, and a second position, where the receiving cavities of the support are disposed in alignment along the feed path in such a way that they pass through the measuring zone one after the other in succession. - a conveyor provided with a plurality of receiving cavities for respective containers and configured to move the receiving cavities along a feed path between a loading station for loading the containers and an unloading station for unloading the containers; - a measuring station located along the feed path between the loading station and the unloading station and configured to inspect each container while the container is being supported and moved by the conveyor, the measuring station comprising a microwave detector provided with a measuring zone through which each container passes, the device further comprising a processing unit configured to receive a measurement signal from the microwave detector and to generate an information item relating to at least one property of the container or of the dose contained therein, preferably density or weight, wherein the conveyor comprises a transporting element defining the feed path and a plurality of supports extending away from the transporting element transversely to the feed path and each having two or more of the receiving cavities, and characterized by each support being rotatable about a swivel axis to adopt at least a first position, where the receiving cavities of the support are disposed in alignment transversely, preferably perpendicularly, to the feed path, and a second position, where the receiving cavities of the support are disposed in alignment along the feed path in such a way that they pass through the measuring zone one after the other in succession.