  We study various moduli spaces of local Shtukas in the setting of Fargues'
program for $GL_n$. In certain cases, this gives us an explicit description of
the spectral action which was recently introduced by Fargues and Scholze. This
description sheds light to the categorical local Langlands program for $GL_n$
and allows us to construct Hecke eigensheaves associated to certain $\ell$-adic
Weil representations of rank $n$ and to prove some parts of Fargues'
conjecture. Moreover, by using this description, we can prove new cases of the
Harris-Viehmann conjecture for non-basic Rapoport-Zink spaces and compute some
parts of the cohomology of the Igusa varieties associated to $GL_n$.
