The Future Circular Collider (FCC) will allow to perform detailed studies on particle physics thanks to the available high statistic and the precision with which the particle energy and beam polarization will be known. In order to exploit such opportunities, very high performance experiments have to be installed at the interaction points. The two baseline options, included in the Conceptual Design Report of FCC are CLD, based on the ILC-like detector design, and IDEA. This last proto-experiment is described in details here below, with particular reference to the achievable performance.