  Within an extended chiral constituent quark model, three- and five-quark
structure of the $S_{01}$ resonance $\Lambda(1405)$ is investigated. Helicity
amplitudes for the electromagnetic decays ($\Lambda(1405) \to
\Lambda(1116)\gamma$, $\Sigma(1194)\gamma$), and transition amplitudes for
strong decays ($\Lambda(1405)\to\Sigma(1194)\pi$, $ K^{-}p$) are drived, as
well as the relevant decay widths. The experimental value for the strong decay
width, $\Gamma_{\Lambda(1405)\to (\Sigma \pi)^\circ}=50\pm 2$ MeV, is well
reproduced with about 50% of five-quark admixture in the $\Lambda(1405)$.
Important effects due to the configuration mixings among
$\Lambda^{2}_{1}P_{A}$, $\Lambda^{2}_{8}P_{M}$ and $\Lambda^{4}_{8}P_{M}$ are
found. In addition, transitions between the three- and five-quark components in
the baryons turn out to be significant in both radiative and strong decays of
the $\Lambda(1405)$ resonance.
