In this work, we analyze the pressure sensing of a thin film molybdenum/aluminumnitride/molybdenum (Mo/AlN/Mo) microwave/RF MEMS filter fabricated by a simple technology. After an experimental characterization in a frequency range between 1 and 36 GHz, we focused on the piezoelectric effect due to the stress properties of the piezoelectric AlN layer by applying forces by means of weights. Variations in the bandpass region of the microwave/RF filter are observed by proving high sensitivity also for low applied weights. We check by a properly designed three-dimensional (3D) finite-element method (FEM) tool the pressure-sensing property of the proposed device. Finally, we analyze the bad gap property of a chip with central defect around 40 GHz.