The invention relates to an apparatus for measuring the velocity of a fluid flow, wherein electrical charge carriers are emitted into the fluid flow (1, 11, 21) from an emitter electrode (3, 13, 23, 33), and wherein an electrical signal caused by this is measured at a sensor electrode (4, 14, 24, 34). The projection of the envelope of the cross-sectional area of that part of the sensor electrode which projects into the fluid flow into the cross-sectional plane of the fluid flow is small in comparison with the cross-sectional area of the fluid flow at this point, if present at all. The measured current (ls) of the sensor electrode (4, 14, 24, 34) is used to serve as a characterizing feature of the velocity of the fluid flow in accordance with a defined allocation function. The measurement method has virtually no delay and can be used in a high temperature and velocity range.