Graphene foam (GF) - a three-dimensional porous structure that comprises several graphene layers - has excellent physical properties and, consequently, exciting possible applications. In this work, we report the mechanical behavior of GFs that were grown using high-temperature chemical vapor deposition (CVD) and subjected to electrostatic tensile loads. We show that such loads reduce the mechanical stiffness of the GF (Young's modulus in the kilo-Pascal range) and release prestresses generated during growth. In addition, GF demonstrates electrostatic resonance. By characterizing the fundamental electromechanical behavior of GF, this Letter paves the way toward the development of novel GF-based devices, such as GF electrostatic resonant sensors, flexible capacitors, and micro- and nanoelectromechanical devices.