The submerged Economics is, by its very nature, very difficult to quantify. All the figures that are handled in this respect are mere approximations, more or less accurate. However, beyond the existing difficulties for its precise measurement, there are indirect indicators that the Economics submerged reaches very notable proportions in our country. Specifically, two phenomena allow us to make this assumption. Firstly, illegal immigration. Only the regularization promoted by the then Minister Caldera brought to light, almost five years ago, the presence in Spain of 700,000 irregular immigrants. No country would attract that issue of people if its labor market lacked alternatives for undocumented workers. The second phenomenon is unemployment. Spain has always maintained fees unemployment rates well above those of the rest of Europe. Such social and economic pressures would be unsustainable without the outlet offered by a strong informal sector.