We consider the zigzag half-nanotubes (tight-binding approximation) in a uniform mag- netic field which is described by the magnetic Schr¨ odinger operator with a periodic potential plus a finitely supported perturbation. We describe all eigenvalues and resonances of this operator, and theirs dependence on the magnetic field. The proof is reduced to the analysis of the periodic Jacobi operators on the half-line with finitely supported perturbations.