While gas and oil produced in shale deposit are the same conventional hydrocarbon substances, this chapter focuses more specifically on shale deposit production because these unconventional fuels have revolutionised the energy panorama not only in the USA but worldwide too. To help a better understanding of the dramatic changes, this chapter will present the geological aspects of shale and the challenges involved in the development of this new technology. Accordingly we trace back the evolution of this new technique and investigate its impact on the environment. The focus of the chapter is not limited to America – we explore the current status of fracking worldwide, and its potential future exploitation. To finish, we look in detail at the legislative framework established in the EU.