The invention relates to a thermal flow sensor comprising: a support, at least one element intended to be vibrated relative to the support, suspension means for said vibrating element relative to the vibrating element, means for heating the vibrating element, means for electrostatic excitation of the vibrating element so as to vibrate it at its resonance frequency, piezoelectric gauges for detecting the resonance frequency variation of the vibrating element, the gauges forming means for heating the vibrating element by Joule effect and the suspension means comprising two beams formed by nanowires so as to reduce the heat losses from the vibrating element toward the support.