Magnetoelectric properties of Fe-based amorphous metals (AM) are calculated within both the cluster ($K_j$) model and the many-electron operator spinors representation. AM are modified by the chemical-bond fluctuations (CBF) and microdiffusion. The wave function of Fe ion consists of wave functions of high-spin (HS, $\xi_3$), low-spin (LS, $\xi_1$), and band ($f_r$) states at the lattice site $r$. Their amplitudes $\xi_j$($T$, $B$) depend on temperature $T$ and magnetic field $B$. As postulated by the Fe—B example, the ferromagnetic clusters of $\alpha$-Fe interact ($A_{31} > 0$) through the LS ions within the hj holes. The Curie temperature $T_c$($\xi_j$) is lowered owing to $A_{31}$ at the AFM exchange with $A11 < 0$ for $h_j$. Ferromagnon exchange hardness, $D(T, \xi_j)$, depends on the CBF through $\xi_j(T)$. The AFM phase is stable, if $|A_{11}| > A_{33}$, and it has two antiferromagnon branches: $E_a \propto k$, $E_0 \cong A_{31}$ for quasi-momentum $k \ll 1$. Cr addition also stabilizes AFM phase owing to the Cr—Cr exchange ($A_{vv} < 0$). Probability of metamagnetic (MM) AFM $\rightarrow$ FM transition is increased by microdiffusion. The number of the nearest Cr—Cr neighbours within the $h_j$ holes is decreasing with the $T$ growing, decreasing $A_{vv}(T)$ at $T \rightarrow T_{MM} — 0$. The MM transitions either at $T_{MM}$ or in the $B_{MM}(T)$ field at $T < T_{MM}$ are accompanied by giant magnetoresistance with $\Delta R \propto \xi_1^2(T)s_T^2(B)$. Mean spin for LS ion is a part of ‘effective mass defect’ $\Delta m^{*}(T, B)$ at $B \rightarrow B_{MM}$. The FM effects such as ferromagnetic anisotropy (FMA) and magnetostriction (FMS) are caused by the LS-Fe—B$^{+}$ spin—orbit coupling in condition of deformation $u_{ij}$. Deformation $u_{ij}$ induces FMA ($K_u \ne 0$) in the process of AM-ribbon fabrication or after annealing. The curve of magnetic susceptibility $\chi(B)$ depends on $K_u$ and $K_1$ within the cluster.