  We propose a new chiral model of metastable supersymmetry breaking in the
conformal window via chiral/nonchiral Seiberg duality, which is focused on
Spin(7)/SU(N_f-4) duality in this letter. Following the approach of
Intriligator-Seiberg-Shih model, a small mass perturbation in the nonchiral
theory leads to supersymmetry breaking by rank condition in the chiral dual
description.
