Poly(ether ether ketone) (PEEK) is an organic: polymer with excellent thermal stability, chemical resistance, and mechanical properties, that are retained at high temperature. In this study, PEEK was sulfonated with concentrated sulfuric acid (98%) at various degrees of sulfonation (DS) using sulfonation tithes between 2 and S h-at a constant temperature of 50 degrees C. The properties and chemical structure of the sulfonated membranes (S-PEEK) Were investigated using TGA, XRD, and FR-IR. In this study, the methanol, permeability, thermal and mechanical properties, and proton conductivity of composite membranes were measured for the effect of Ferrierite zeolite as inorganic filler at various amounts (5, 10, 15, 17, and 20% v/v). The proton conductivity and Methanol permeability values. of the composite membranes were measured compared to those of commercial membrane, Nafion 117.