A collimator system for extracting 14 MeV-neutron beam has been devised by utilizing a shield assembly for the streaming experiment at Fusion Neutronics Source (FNS) facility at JAERI. The collimator consists of a 500 mm pre-collimator and a 1.2 m iron bulk shield followed by 400 mm polyethylene and 200 mm lead layer, at the center of which a hole of 20 mm in diameter penetrates along the horizontal line from a 14 MeV source. The collimated beam's characteristics are experimentally studied in terms of beam on/off ratio, neutron flux spectrum at the exit of collimator hall by using an imaging plate, activation foils, and NE213 scintillator. It was found that the background level at an off-neutron-beam is low enough to make an in-beam experiment effective. Using the collimated beam, a series of secondary gamma-ray production cross section measurements were conducted without pulse mode operation.