In this paper, the detection and quantification of the moisture content in epoxy and polyamide-6 using a non-destructive and portable device based on a microwave resonator technique is reported. Parameters related to the real (ε′) and imaginary (ε″) part of the complex permittivity were used to quantify the moisture content in these polymers. The maximal penetration and analyzing depth of the microwaves through polyamide-6 (both at least of 7.35 mm) and epoxy (24 mm and 12 mm, respectively) were measured performing samples with different thicknesses. Moreover, measurements were performed at different distances from the sample surface being possible to perform contactless measurements.