A continuous zone-drawing/zone-annealing method was applied to poly(ethylene terephthalate) fibers in order to improve their mechanical properties. Apparatus used for this treatment was assembled in our laboratory. The continuous zone-drawing treatment was carried out at a drawing temperature of 103 degrees C under an applied tension of 6.6 MPa to fully orient amorphous chains in the drawing direction without inducing thermal crystallization. The continuous zone-annealing treatment was carried out twice at an annealing temperature of 160 degrees C under 102.2 MPa and at 183 degrees C under 161.1 MPa to crystallize the highly oriented amorphous chains. The fiber was continuously drawn and annealed at a rate of 420 mm/min. The fiber obtained had a birefringence of 0.260, a degree of crystallinity of 55%, a tensile modulus of 18 GPa, and a storage modulus of 21 GPa at 25 degrees C. Despite the large difference in the treating speed between the continuous zone-annealing and zone-annealing, their values are approximately equal to those of the zone-annealed PET fiber that was reported previously.