This paper describes the structures of the first industrial era with an iron construction. In the first part, iron is presented as a chemical element, its physical and chemical properties, its distribution on Earth, the way iron is obtained, the use and history of its applications in construction before the industrial revolution. After that are mentioned the general features of the industrial revolution and the most important inventions, achievements and changes in the technology and construction that it has led to. The most important typologies, constructions and structures of the first industrial era in which is used iron are described in more detail. As the most important typology, there were factories, greenhouses, exhibition halls and public and residential architecture, where the most prestigious public buildings are the railway stations, galleries, markets and libraries. Also described in detail is the mass production of iron and the appearance of new iron constructive elements and their use. In the last part, the application of iron was analyzed in the selected example of the Crystal Palace, which architect was Joseph Paxton.