A microfluidic device for concentrating particles contained in a fluid sample, comprising a substrate having a surface at which at least one microfluidic arrangement is defined, which comprises: - a loading chamber, for loading the fluid sample into the at least one microfluidic arrangement; - a plurality of microchannels, which have respective inlet ends extending from the loading chamber, the microchannels of the plurality being fluidically connected in parallel to said chamber and set side by side; - a covering element, which is substantially impermeable to the fluid sample and extends at least partially over the plurality of microchannels, wherein the loading chamber and the plurality of microchannels extend substantially according to a plane identified by the substrate, wherein: - the loading chamber and the plurality of microchannels are in the form of cavities or surface etchings of the substrate, - each microchannel of the plurality is closed at its longitudinal end opposite to the inlet end, and - the microchannels of the plurality are partially delimited, at least at an accumulation region thereof generally opposite to the respective inlet ends, by a filter element which is permeable at least to air, is set on top of at least a stretch of the microchannels of the plurality, and is configured for withholding within each microchannel possible particles that may be present in the fluid sample, in such a way that particles possibly contained in a volume of fluid of the fluid sample that penetrates into each microchannel tend to concentrate in the respective accumulation region as a result of a force applied to at least one of the microfluidic device and the fluid sample loaded into the loading chamber, such as a centrifugal force caused by a rotation of the substrate about a centre of rotation, or a positive pressure applied on the fluid sample at the loading chamber, or a negative pressure applied on the fluid sample at the accumulation regions of the microchannels. - a loading chamber, for loading the fluid sample into the at least one microfluidic arrangement; - a plurality of microchannels, which have respective inlet ends extending from the loading chamber, the microchannels of the plurality being fluidically connected in parallel to said chamber and set side by side; - a covering element, which is substantially impermeable to the fluid sample and extends at least partially over the plurality of microchannels, wherein the loading chamber and the plurality of microchannels extend substantially according to a plane identified by the substrate, wherein: - the loading chamber and the plurality of microchannels are in the form of cavities or surface etchings of the substrate, - each microchannel of the plurality is closed at its longitudinal end opposite to the inlet end, and - the microchannels of the plurality are partially delimited, at least at an accumulation region thereof generally opposite to the respective inlet ends, by a filter element which is permeable at least to air, is set on top of at least a stretch of the microchannels of the plurality, and is configured for withholding within each microchannel possible particles that may be present in the fluid sample, - the loading chamber and the plurality of microchannels are in the form of cavities or surface etchings of the substrate, - each microchannel of the plurality is closed at its longitudinal end opposite to the inlet end, and - the microchannels of the plurality are partially delimited, at least at an accumulation region thereof generally opposite to the respective inlet ends, by a filter element which is permeable at least to air, is set on top of at least a stretch of the microchannels of the plurality, and is configured for withholding within each microchannel possible particles that may be present in the fluid sample, in such a way that particles possibly contained in a volume of fluid of the fluid sample that penetrates into each microchannel tend to concentrate in the respective accumulation region as a result of a force applied to at least one of the microfluidic device and the fluid sample loaded into the loading chamber, such as a centrifugal force caused by a rotation of the substrate about a centre of rotation, or a positive pressure applied on the fluid sample at the loading chamber, or a negative pressure applied on the fluid sample at the accumulation regions of the microchannels.