To provide polyparaphenylene terephthalamide (PPTA) staple fibers which hold the original high heat resistance and high Young's modulus thereof, have a small ion content, and are especially useful for electric/electronic parts, and to provide uses thereof.

The polyparaphenylene terephthalamide (PPTA) staple fibers having a Na+ ion content of ≤1.0 wt.% and obtained by subjecting fibers having a crystal size (110 face) of ≤50, a diameter of 1 to 20 μm, and an aspect ratio of 50 to 5,000 to an extraction treatment using 20°C water. The staple fibers can be used for insulating/low dielectric materials, resin composite materials, rubber-composite materials or sheet-like structures for printed circuit boards.