  We introduce the concept of black shell, consisting on a massive thin
spherical shell contracting toward its gravitational radius from the point of
view of an external observer far from the shell, in order to effectively model
the gravitational collapse. Considering complementary description of
entanglement entropy of a black shell and according to Gibbons-Hawking
Euclidean approach, we calculate the Bekenstein-Hawking entropy retrieving
horizon integral and discarding boundary at infinity.
