NOVELTY - A reinforced electrolyte membrane (1) has an electrolyte membrane (10) containing a fluorine-containing polymer having an ion-exchange group and is reinforced with a woven fabric (20) containing reinforcing yarns (22) and sacrifice yarns (24). The sacrifice yarns remain in the electrolyte membrane (10), and voids are formed around the sacrifice yarns and between the electrolyte membrane, and satisfie specified relations (i) and (ii).    USE - Reinforced electrolyte membrane is used as ion-exchange membrane. Uses include but are not limited to alkali-chloride electrolyte decomposition process, diffusion dialysis, ozone generation electrolysis, electrolytic reduction, diaphragm of fuel cell and polymer catalyst.    ADVANTAGE - The reinforced electrolyte membrane is manufactured without producing crack.    DETAILED DESCRIPTION - A reinforced electrolyte membrane (1) has an electrolyte membrane (10) containing a fluorine-containing polymer having an ion-exchange group and is reinforced with a woven fabric (20) containing reinforcing yarns (22) and sacrifice yarns (24). The sacrifice yarns remain in the electrolyte membrane (10), and voids are formed around the sacrifice yarns and between the electrolyte membrane, and satisfies relations: 2000 mu m2 more than A less than 6000 mu m2 (i), and B/A=0.3 or more and less than 1 (ii), where A sum of the cross-sectional area of the sacrifice yarn and cross-sectional area of the void, and B is the cross-sectional area of the sacrifice yarn. An INDEPENDENT CLAIM is included for manufacture of reinforced electrolyte membrane, which involves contacting the reinforced precursor membrane reinforced with the woven fabric, with an alkaline aqueous solution, hydrolyzing precursor group contained in fluorine-containing polymer of the precursor membrane, and converting into the ion exchange group.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of reinforced electrolyte membrane.    Electrolyte membrane (1)    Electrolyte membrane (10)    Woven fabric (20)    Reinforcing yarns (22)    Sacrifice yarns (24)