The aim of this work is to study the diffusion of the changes towards a diversified manufacturing structure in the different Spanish regions during the first third of the XXth century and the evaluation of the factors which explain the manufacturing industrial growth of these regions. The considerated factors are the localization economies (Marshall's externalities of specialization) and the urbanization economies (externalities of diversity or Jacobs's externalities). Owing to the non-existence of an industrial census in Spain, we estimate a data set based on a reconstruction of the industrial direct taxes in 1913 and 1929, for 50 provinces and 20 manufactures. We find that in this period of creating of an important manufacturing basis to realize the industrialization process, the different regions did not increase their specialization and, the urbanization economies were even positive to the manufacture growth between 1913 and 1929.