Study of $\eta$-meson Decays at KLOE/KLOE-2

Working at a $\varphi$-factory, KLOE/KLOE-2 has collected a very large and clean sample of $\eta$ decays, which allow to perform a variety of precision measurements. This report presents the recent results on the $\eta$-meson decays from KLOE/KLOE-2 experiments, including the search of the $C$-violating decay $\eta \to \gamma \gamma \gamma$, the determination of the $CP$ asymmetry in $\eta \to {\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$, the precision measurement of the $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0$ Dalitz plot distribution, the search for the $CP$-violating decay $\eta \to {\pi }^{+}{\pi }^{-}$ and the precision measurement of $\mathcal{O}(p^6)$ dominated decay $\eta \to \gamma \gamma {\pi }^0$.