  We evaluate the $\pi N$ compositeness of the $\Delta (1232)$ resonance so as
to clarify the internal structure of $\Delta (1232)$ in terms of the $\pi N$
component. Here the compositeness is defined as contributions from two-body
wave functions to the normalization of the total wave function and is extracted
from the $\pi N$ scattering amplitude. In this study we employ the chiral
unitary approach with the interaction up to the next-to-leading order plus a
bare $\Delta$ term in chiral perturbation theory and describe $\Delta (1232)$
in an elastic $\pi N$ scattering. Fitting the $\pi N$ scattering amplitude to
the solution of the partial wave analysis, we obtain a large real part of the
$\pi N$ compositeness for $\Delta (1232)$ comparable to unity and
non-negligible imaginary part as well, with which we reconfirm the result in
the previous study on the $\pi N$ compositeness for $\Delta (1232)$.
