In this paper, a resonator and second order filter are fabricated using a novel technological process based on micromachining and thermo-diffusion. The use of this innovative process opens the way to the design of RF components relying on partially air-filled Substrate Integrated Waveguides (SIW). These topologies and particularly the proposed partially air-filled pedestal SIW resonator is suitable to design high-Q, yet compact SIW resonators. In this paper, a study of partially air-filled pedestal SIW resonator is proposed to offer an optimized trade-off between Q-factor and compactness. Then, based on this study, a partially airfilled pedestal resonator working at 5 GHz is designed and manufactured. The measured prototype exhibits a Q-factor of 285, which represents a 53 % increase in Q-factor compared to a fully dielectrically-filled-in pedestal SIW resonator, while the size is kept constant. Finally, a second order filter based on this resonator topology is also designed, measured and discussed.