The neutron-production double-differential cross sections for the neutron-induced reaction were measured on iron and lead samples up to 100 MeV. Neutrons produced by a 800 MeV proton-bombarded spallation target were used as incident particles. The energies of incident neutrons were determined by their flight times on the path between the neutron source and the detectors. A fission ionization detector was utilized to determine the incident-neutron flux. NE213 liquid organic scintillators were employed to detect outgoing neutrons which were emitted from the sample. As a part of this experiment, the response functions of NE213 detectors for neutrons were also measured by using the spallation neutrons. The energy spectra for outgoing neutrons were derived from their deposition-energy spectra and the measured response functions of the detectors with unfolding technique. The results were presented at incident energies around 100 MeV, and were compared with GNASH calculations.