The present work demonstrates the disintegration of thin electrically exploding tungsten wires in a vacuum. The drawn tungsten wires split into tiny fibers in a time close to that at which the wire reaches its melting point. Similar results were obtained for wires exploded at low pressures and at atmospheric pressure. The results show, within the limits of the experimental accuracy, that, when the wire reaches its melting point, dips are observed on the current derivative and the voltage oscillograms and x rays are produced. The results support the suggestion that the production of hard x rays from drawn thin exploding tungsten wires is due to the splitting of the wire, which has a fiberlike crystalline structure. Moreover the oscillograms of the first current pulse show that for thin wires the electrical conduction up to melting point is due only to the solid wire material and that the influence of the ambient pressure on the crest value of the first current pulse for wires exploded at the same condenser‐bank voltage is almost negligible.