Su-8 polymer has excellent potential for application in process manufacturing. This paper presents the effects of thermal stress on the electromagnetic properties of SU-8 polymer, showing the frequency-dependent microwave response of the material. The procedure follows the international standard method for assessing the quality of components and devices for space qualification as thermal stress simulates the aging process. The polymer has been used as a base layer to fabricate passive devices in the coplanar waveguide (CPW) configuration. Resonating structures and delay lines, with different sizes, have been manufactured on a SU-8 layer spun on a high resistivity silicon wafer. The material's dielectric constant has been calculated by measuring the microwave response of the devices before and after the thermal processes. We have recorded data in a broadband range, from 2 GHz to 18 GHz, and the …