Chapter 15 looks at the new set of investigative measures introduced by the reform of the Criminal Procedure Code in Spain, in 2015, which changed completely the approach to the investigation of cybercrime, transformed now into one of the most modern in Europe. The new regulation introduced the latest high-tech investigative tools, imposing a complete set of duties of cooperation on all internet service providers. However, the Spanish legislator failed to amend the domestic legal framework on electronic communications data retention, and so it is not compatible with the jurisprudence of the Court of Justice of the EU. This chapter describes the rules as developed and applied by the Spanish courts, before and after the amendments of the Criminal Procedure Code 2015, and several subsequent laws on digital data that, since then, have been adopted in reaction to the EU’s legal framework in the field.