The neutron energy spectrum at the beam port has been measured at many boron neutron capture therapy (BNCT) facilities worldwide. At Heavy Water Neutron Irradiation Facility of Kyoto University Research Reactor (KUR-HWNIF), two types of neutron spectrometers-the Simple Multilayer Spectrometer (SMS) and the Cylindrical Hemisphere-Accurate Remote Multilayer Spectrometer (CHARMS)-were recently developed to measure the neutron energy spectrum. This paper investigates the characteristics of each neutron spectrometer in measuring the neutron energy spectrum at BNCT irradiation field, with a focus on their dependence on the angular distribution of the incident neutron beam. Additionally, an overview of the CHARMS prototype designed to verify online and remote operation from outside the irradiation room is provided.