We optimize the composition of tellurite glass for the manufacture of photonic crystal fibers with a large spectrum of transparency. The glasses, synthesized in four and five component (TeO2-WO3-Na2O-Nb2O5 and TeO2-WO3-PbO-Na2O-Nb2O5) oxide systems with variable contents of WO3 (5–38 mol%) and PbO (0–18 mol%), are designed and manufactured, and the transmission properties of the obtained glasses for the spectral range of 200 nm–7 μm have been determined. Thermal expansion coefficients and glass characteristic temperatures are determined by the dilatometer and Leitz heat microscope methods. Differential Scanning Calorimetry (DSC) measurements as well as crystallization tests by isothermal heat treatment are used to measure the thermal stability of the glasses and their ability to crystallize. Diffractive X-ray (XRD) measurements are used to determine the crystalline phases of the glass samples and the glasses with the highest resistance to recrystallization during thermal treatment were selected and used for the manufacture of photonic crystal fibers.