An IEC rotary vane electroscope with metal vane. A robust unit that has high sensitivity when detecting electrostatic charge. A very thin metal vane is carefully pivoted and balanced in a small frame inside a container with glass sides. When a charge is deposited on the electrode disc at the top of the electroscope, the vane pivots and deflects. A 4mm socket is provided for earthing the metal casing. One glass side panel is removable for accessibility.