This book reviews advances in cutting-edge micro-/nano-electrometers, and discusses the technological challenges involved in their practical implementation. The detection of electrostatic charge has a wide range of applications in ionization chambers, bio-analyte and aerosol particle instruments, mass spectrometers, scanning tunneling microscopes, and even quantum computers. Designing micro-/nano-electrometers (also known as charge sensors) for electrometry is considered vital because of the charge sensitivity and resolution issues at micro-/nano-scales. The remarkably dynamic microelectromechanical systems (MEMSs)/nanoelectromechanical systems (NEMSs), and advances in solid-state electronics, hold considerable potential for the design and fabrication of extremely sensitive charge sensors.