It is well known that the enhancement of halo neutron removal cross sections in neutron halo nuclei. This is one of the evidence for the neutron halo structure. Because the valence neutron of the isomeric state in 16N is considered to be mainly occupying in the s-orbital, we studied the nuclear structure of 16N as a candidate for neutron halo nucleus. In this study, we measured one-neutron removal cross sections σ-1n using secondary beams of 16N with a mixture of ground and isomeric states. We used two types of primary beams, 15N and 18O, to produce 16N beams with different isomeric ratios (8.7, 24.2a 16N beam with a large isomeric ratio is large compared to that obtained with another beam with a small isomeric state. This result suggests that the 16N isomeric state is considered to have a neutron-halo-like structure.