Saturated and unsaturated transverse permeability of quasi-unidirectional carbon fiber fabric have been measured with a new test bench equipped with micro-thermocouples. A temperature gradient is detected when the cold fluid enters in contact with the thermocouples. The developed methodology allows tracking the flow front with accuracy in a sample stack which does not exceed 3 mm. Saturated and unsaturated permeability are compared for different fiber volume fractions, between 43 % and 64 %. The decrease of permeability with increased fiber volume fraction is coherent with the Kozeny-Carman’s relation. Thanks to the high resolution in pressure measurement, transient effects can be evidenced in a single ply.