An isolating switch is a switch device primarily used for "isolating power, switching off, and connecting or disconnecting low current circuits" without arc extinguishing capabilities. When in the open position, the switch contacts have a specified insulating distance and a clear disconnection mark; when in the closed position, it can carry the current under normal circuit conditions and the current under abnormal conditions (such as a short circuit) within a specified time. Generally used as a high-voltage isolating switch, i.e., an isolating switch with a rated voltage above 1kV. Its working principle and structure are relatively simple, but due to its high usage volume and strict reliability requirements, it has a significant impact on the design, establishment, and safe operation of substation and power plant. The main feature of an isolating switch is its lack of arc extinguishing capability, which can only open or close the circuit under no-load current conditions. This entry covers the function, features, types, applications, anti-misoperation improvements, maintenance, and common issues of isolating switches.