A
tungsten wire containing 1 to 10% by
mass of
rhenium has a point which indicates a 2% elongation within a quadrangle formed by joining points with straight lines, where the values of x and y are point (20, 75), point (20, 87), point (90, 75), and point (90, 58), in this order, wherein the wire
diameter of the aforementioned
tungsten wire is represented by x mum, and the elongation of the
tungsten wire is 2% after electrically heating with an
electrical current which is a ratio of y % to the fusion current (FC) at the wire
diameter x mum, and wherein a semi-logarithmic
system of coordinates is expressed by a
horizontal axis using a
logarithmic scale of the aforementioned wire
diameter x and a
vertical axis using a normal scale of ratio y to the fusion current. According to the above-described configuration, a tungsten wire having a great elongation even under conditions of high temperature can be provided, and the tungsten wire can exhibit an excellent durability when used as component material for constituting
cathode heaters and so forth, and the tungsten wire can be manufactured efficiently.