The iron and steel industry is characterised by high energy and material consumption. Due to the volatile steel market, rising energy prices and CO2-emissions, energy and material efficiency is increasingly becoming a decisive competitive factor for European companies in the iron and steel industry. Industry 4.0 applications offer new opportunities to increase resource efficiency in order to ensure the competitiveness of steel companies. This master thesis presents the potential and challenges of Industry 4.0 for the iron and steel industry and aims to show, what contribution Industry 4.0 can make, to increasing energy and material efficiency in the iron and steel industry. For this purpose, based on a detailed literature study, guideline-based expert interviews with persons from the iron and steel industry were conducted. In addition, best practice examples of Industry 4.0 applications, that improve energy and material efficiency in the steel industry, were identified and analysed. The results show, that an improvement in energy and material efficiency in the processes of the iron and steel industry with Industry 4.0 applications, is achieved mainly by reducing scrap, increasing output and by optimal process control through the use of models and simulation. In the identified Industry 4.0 applications, mainly Big Data technologies as well as modelling and simulation are applied. However, it should be noted that the implementation of Industry 4.0 in the steel industry is mainly focused on the optimization of product quality and an improvement of resource efficiency is often only a positive side effect. Although a direct link between Industry 4.0 applications and resource efficiency is currently difficult to establish, energy and material efficiency is an important factor in maintaining competitiveness. The major obstacles to the implementation of Industry 4.0 in the iron and steel industry have been identified as the low acceptance by employees, the difficult integration of digital solutions into existing structures and the specific environmental conditions. The first implemented Industry 4.0 solutions already show, that the iron and steel industry is ready and open for Industry 4.0. Nevertheless, there is still enough need for action along the interlinked processes of the steel industry in the implementation of Industry 4.0 applications to improve energy and material efficiency.