In many eddy current problems, surface impedance conditions are currently used to avoid the modelling of the skin depth in volumes. In the finite element method context, such conditions lead to surfaces elements at boundaries of massive conductors, or to shell elements representing thin layers, which unfortunately require a complex specific implementation in the codes. We propose here a new shell finite element easy to implement in the standard (A-φ) and (T-Ω) formulations. The advantage of this element is to be arbitrarily thick, so it takes into account some end-effects at its perimeter such as the connection between shell an 3D regions. The basic principles of the thick shell as well as a three-dimensional validation test dealing with a magnetic core-fault are presented.