  We use the PLANCK 2018 and the WMAP data to constraint inflation models
driven by a scalar field $\phi$ in the presence of the non-minimal
scalar-curvature mixing term $\frac{1}{2}\xi R \phi^2$. We consider four
distinct scalar field potentials $\phi^p e^{-\lambda\phi},~(1 -
\phi^{p})e^{-\lambda\phi},~(1-\lambda\phi)^p$ and
$\frac{\alpha\phi^2}{1+\alpha\phi^2}$ to study inflation in the non-minimal
gravity theory. We calculate the potential slow-roll parameters and predict the
scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$, in the
parameters ($\lambda, p, \alpha$) space of the potentials. We have compared our
results with the ones existing in the literature, and this indicates the
present status of non-minimal inflation after the release of the PLANCK 2018
data.
