A method of producing a nano/micro fibrous filter substrate for sampling aerosol particles comprising at least three fibrous layers (Layer 1, 2, 3), the method comprising at least: • stage (4.1) of producing the first layer (Layer 1) as a structural microfibrous support layer, comprising steps of ∘ (4.1.1) extruding a polymer filament, ∘ (4.1.2) conditioning the extruded filament, ∘ (4.1.3) 3D-printing the first layer from the conditioned filament; • stage (4.2) of producing the second layer (Layer 2) as a micro/nano mesofibrous binding layer, comprising steps of ∘ (4.2.1) applying the produced first layer (Layer 1) to a collector, ∘ (4.2.2) providing a polymer solution for the second layer (Layer 2), ∘ (4.2.3) producing the second layer (Layer 2) by electrospinning said polymer solution on the surface of the first layer (Layer 1); • stage (4.3) of producing the third layer (Layer 3) as the nanofibrous surface layer for the collection of aerosol particles, comprising steps of ∘ (4.3.1) providing a polymer solution for the third layer (Layer 3), ∘ (4.3.2) producing the third layer (Layer 3) by electrospinning said polymer solution on the surface of the second layer (Layer 2); • stage (4.4) of postprocessing the substrate, comprising steps of ∘ (4.4.1) drying the fabricated substrate; ∘ (4.4.2) removing static charge from the fabricated substrate; ∘ optionally, (4.4.3) sterilizing the fabricated multi-layered substrate. • stage (4.1) of producing the first layer (Layer 1) as a structural microfibrous support layer, comprising steps of ∘ (4.1.1) extruding a polymer filament, ∘ (4.1.2) conditioning the extruded filament, ∘ (4.1.3) 3D-printing the first layer from the conditioned filament; ∘ (4.1.1) extruding a polymer filament, ∘ (4.1.2) conditioning the extruded filament, ∘ (4.1.3) 3D-printing the first layer from the conditioned filament; • stage (4.2) of producing the second layer (Layer 2) as a micro/nano mesofibrous binding layer, comprising steps of ∘ (4.2.1) applying the produced first layer (Layer 1) to a collector, ∘ (4.2.2) providing a polymer solution for the second layer (Layer 2), ∘ (4.2.3) producing the second layer (Layer 2) by electrospinning said polymer solution on the surface of the first layer (Layer 1); ∘ (4.2.1) applying the produced first layer (Layer 1) to a collector, ∘ (4.2.2) providing a polymer solution for the second layer (Layer 2), ∘ (4.2.3) producing the second layer (Layer 2) by electrospinning said polymer solution on the surface of the first layer (Layer 1); • stage (4.3) of producing the third layer (Layer 3) as the nanofibrous surface layer for the collection of aerosol particles, comprising steps of ∘ (4.3.1) providing a polymer solution for the third layer (Layer 3), ∘ (4.3.2) producing the third layer (Layer 3) by electrospinning said polymer solution on the surface of the second layer (Layer 2); ∘ (4.3.1) providing a polymer solution for the third layer (Layer 3), ∘ (4.3.2) producing the third layer (Layer 3) by electrospinning said polymer solution on the surface of the second layer (Layer 2); • stage (4.4) of postprocessing the substrate, comprising steps of ∘ (4.4.1) drying the fabricated substrate; ∘ (4.4.2) removing static charge from the fabricated substrate; ∘ optionally, (4.4.3) sterilizing the fabricated multi-layered substrate. ∘ (4.4.1) drying the fabricated substrate; ∘ (4.4.2) removing static charge from the fabricated substrate; ∘ optionally, (4.4.3) sterilizing the fabricated multi-layered substrate.