COLLISION OF A NON-RELATIVISTIC PARTICLE WITH A STRUCTURAL TARGET V.A. Sidorovich Skobeltsyn Institute of Nuclear Physics, Moscow State University A new version of scattering theory is presented as an example of the collision of a non-relativistic spinless particle with a structural target. The isometric time-dependent wave transformation operators have been introduced and the correct expression for the scattering S-matrix have been obtained. In the present version the non-physical procedures of 'switching-on' and 'switching-off' an interaction do not apply.