  The inverse scattering problem for the relativistic three-dimensional
equation $\Bigl(2E_{\bf p'}-2E_{\bf p}\Bigr)<{\bf p'}|\Psi_{\bf p}>= -\int
V(t)d^3{\bf p''}<{\bf p''}|\Psi_{\bf p}>$ with $E_{\bf p}=\sqrt{m^2+{\bf p}^2}$
and $t=\Bigl(E_{\bf p'}-E_{\bf p''}\Bigr)^2 -\Bigl({\bf p'}-{\bf p''}\Bigr)^2$
is considered. The field-theoretical potential $V(t)$ of this equation is
constructed in the framework of the old perturbation theory. It contains all
contributions of diagrams with intermediate off-mass shell particles. In
particular, this potential reproduces the OBE Bonn model of the $NN$ potential
exactly.For the $\pi N$ scattering it is generated by $\sigma,\rho,
\omega$-meson exchange diagrams. The inverse scattering problem is solved by
reduction of these relativistic equations to the standard Schr\"odinger
equations $\Bigl(\Delta_{\bf r}+{\bf k}^2\Bigr)<{\bf r}|\phi_{\bf p}>= - v({\bf
r})<{\bf r}|\phi_{\bf k}>$ with $E_{\bf p}={\bf k}^2/2m+m$. The relation
between the relativistic potential $V(t)$ and its nonrelativistic
representation $v({\bf r})$ is obtained.
