  A spiral fiber tracker (SFT) has been designed and produced for the J-PARC
E36 experiment as an element of the tracking system for conducting a
high-resolution momentum measurement of charge particles from kaon decays. A
novel technique to wind the pre-made fiber ribbons spirally was employed for
the configuration with four detector layers made of 1 mm diameter plastic
scintillating fibers. Good position alignment and sufficiently high detection
efficiency for charged particles with minimum ionizing energy were confirmed in
cosmic ray test. The tracker was successfully used in the E36 experiment.
