It is shown using a both conventional and algebraic approach to quantum fie
ld theory that it is impossible to perform quantization on Unruh modes in M
inkowski space-time. Such a quantization implies setting a boundary conditi
on for the quantum held operator which changes the topological properties a
nd symmetry group of space-time and leads to a field theory in two disconne
cted left and right Rindler space-times. It means that the "Unruh effect" d
oes not exist. (C) 1999 Elsevier Science B.V.