PEI has wide applications in the electronics field, primarily in the manufacture of high-temperature resistant and high-reliability electronic components. Typical applications include fiber optic connectors (due to their low CTE and low optical loss), 5G base station filters, RF connector insulators, circuit boards, coil frames, and LED lamp reflectors.

With its excellent high-temperature resistance, flame retardancy, and dimensional stability, PEI is an important material in the aerospace industry. It is used to manufacture aircraft cabin interior panels, seat backs, food trays, instrument panels, and various structural components. PEI can also be used to manufacture lightweight composite materials, replacing metal parts to achieve weight reduction.

In the automotive field, PEI is mainly used to manufacture components that need to withstand high temperatures and chemical corrosion. Applications include automotive headlight lenses, taillights, fuel system components, sensor housings, ignition system parts, and high-temperature connectors around the engine.

PEI has excellent resistance to sterilization (such as autoclaving) and biocompatibility, thus playing an important role in medical device manufacturing. It is used to manufacture surgical instrument handles, sterilization trays, dental equipment, laboratory animal cages, and housings for ventilators and anesthesia machines.