Quantization of the relativistic particle

We revise the problem of quantizing the relativistic particle. We present t he modified canonical scheme, which allows us to construct the consistent r elativistic quantum mechanics as well as to incorporate arbitrary backgroun ds. This quantum mechanics literally reproduces the one-particle sector of the corresponding quantum field theory. Moreover, this construction gives a possible solution for the well known, old problem of how to construct a co nsistent quantum mechanics on the basis of a relativistic wave equation.