A microfluidic element for analysis of a fluid sample having a substrate and a microfluidic transport system having a channel structure enclosed by the substrate and a covering layer. The channel structure comprises a channel with two side walls as well as a chamber that is in fluid communication with the channel. The chamber has a chamber wall with an inlet orifice. The channel comprises a channel section and a valve section adjoining the channel section, wherein the valve section is in fluid communication with the inlet orifice in the chamber wall in such a way that a fluid can flow from the channel through the valve section and into the chamber. The valve section has a fluid transport cross-section, which enlarges in flow direction. The fluid transport cross-section in the valve section is greater than the fluid transport cross-section in the preceding channel section.