PURPOSE: To produce aromatic polyetherketone monofilament for industrial material having a high silk factor excellent in knot strength, loop strength and circularity of cross section and reduced in yarn unevenness in the direction of fiber axis.

CONSTITUTION: An aromatic polyetherketone having ≥0.8 intrinsic viscosity is subjected to melt spinning at a spinneret temperature of (Tn+20°C) to (Tn+45°C) and passed through a heating cylinder installed immediately under the spinneret and having 100-250°C gas atmospheric temperature and then cooled and solidified in a water bath provided at the position which 5-30cm lower from whitening point and kept at 94°C and then drawn in a gas atmosphere at a temperature exceeding Tg and lower than (Tn+40°C).