The certification verifies the design and performance of the turbine to international standards and is seen as a key milestone to the market.
Gamesa said the turbine would generate 3% more power than its slightly smaller predecessor, the 5MW G128.
The prototype G132 turbine was installed at Gamesa's Alaiz facility in the mountainous region of northern Spain.
The turbine was fitted with 64.5-metre long blades in April 2015, following certification of the G128 model. Gamesa said the blades were the longest to have been transported in Spain.
Gamesa is currently in the process of merging with German manufacturer Siemens. Siemens' portfolio of turbines currently does not include a 5MW machine, however it has a 4MW offshore turbine.