The effect of the power and scanning speed of СО₂-laser radiation on the surface of fused silica for the manufacture of microchannels and microreservoirs for microfluidics tasks is investigated. The dependences of the size and roughness of microstructures on the parameters of laser radiation are established. The depth of microfluidic elements reaches 45 µm with a roughness of < 40 nm.The velocity of liquid propagation (up to 15mm/s) is estimated for the fabricated microchannels. The wettability of microreservoirs is estimated, where the wetting angle reaches 64 ± 7°. The fabricated elements have a high transmission (T≥ 0.8) in the visible spectral range.