  Consider a polynomial F such that each variable appears in exactly one
monomial. The hypersurface defined by the polynomial F is called a hypersurface
with separable variables. A variety is called rigid if there are no nontrivial
actions of the additive group of the ground field on it. If a variety is rigid,
then it is known that in the automorphism group there exists a unique maximal
torus. We describe the automorphism group of a rigid hypersurface with
separable variables, in particular we show that it is a finite extension of the
maximal torus.
