Abstract: This invention relates to a method for disentangling hollow carbon microfibers and to the dispersion of hollow carbon microfibers, preferably having an outer diameter of 3.5 to 70 nm and an aspect ratio of at least 5, to form transparent electrically conductive films. Hollow carbon microfibers, treated with strong acids such as sulfuric acid or oleum and an oxidizing agent such as nitric acid, are disentangled and dispersed homogeneously in a polar solvent. The slurry in which the microfibers are suspended can be coated on a substrate. The coating film is dried and a transparent electrically conductive film is formed. A carbon microfiber aggregation film with excellent transparency is obtained having a total transmittance of at least 80 percent and a haze value of at most 0.1%.