The paper proposes a novel instrument for eddy current non-destructive testing on conductive materials. The instrument is composed by a smart eddy current probe, based on a Giant Magneto Resistance sensor, and a suitable processing unit. Key features of the proposed instrument are the capability of detecting, locating, and characterizing thin defects as superficial and sub-superficial cracks. The main goal of the proposal is the realization of a very low cost instrument that is able to reach performance comparable with instrumentation available on the market and especially suited for application fields such as aerospace and maritime. In the paper the steps followed for the instrument realization together with its experimental characterization are described in detail.