In the present paper we continue the project of systematic
construction of invariant differential operators on the example of
the non-compact exceptional Lie algebra $F'_4$ which is split real form of the exceptional Lie algebra $F_4$. We consider induction from a maximal parabolic algebra. We classify the reducible Verma modules over $F_4$ which are compatible with this induction.
Thus, we obtain the classification of the corresponding invariant differential operators.