Let
![]()
and
![]()
be algebraically closed fields of characteristics
p>0 and 0, respectively. For any finite group
G we denote by
![]()
the
modular representation algebra of
G over
![]()
where
![]()
is the Grothendieck group of finitely generated
![]()
-modules with respect to exact sequences. The usual operations induction, inflation, restriction, and transport of structure with a group isomorphism between the finitely generated modules of group algebras over
![]()
induce maps between
modular representation algebras making
![]()
an inflation
functor. We show that the composition factors of
![]()
are precisely the simple inflation
functors
![]()
where
C ranges over all nonisomorphic cyclic
p′-groups and
V ranges over all nonisomorphic simple
![]()
-modules. Moreover each composition factor has multiplicity 1. We also give a filtration of
![]()
.