  The integrability of the one-dimensional (1D) fermion chain model is
investigated in the framework of the Quantum Inverse Scattering Method (QISM).
We introduce a new R-operator for the fermion chain model, which is expressed
in terms of the fermion operators. The R-operator satisfies a new type of the
Yang-Baxter relation with fermionic L-operator. We derive the fermionic
Sutherland equation from the relation, which is equivalent to the fermionic Lax
equation. It also provides a mathematical foundation of the boost operator
approach for the fermion model. In fact, we obtain some higher conserved
quantities of the fermion model using the boost operator.
