J. Chalupský, L. Juha, V. Hájková, T. Burian and J. Cihelka from the Department of Radiation and Chemical Physics, Institute of Physics ASCR, v.v.i., and M. Kozlová from Department of Ultra-intense Lasers, Institute of Physics ASCR, v.v.i., carried out in a wide international collaboration lead by a group from the Clarendon Laboratory (Oxford) several series of experiments at the FLASH facility (HASYLAB/DESY, Hamburg) demonstrating of a new finding of self-induced trasparence of aluminium in the soft X-ray spectral region at an extreme irradiance level. The full text >>