To carry out assembly work and the adjusting the tension and meandering of a conveyor belt in a wide space and to enable conveyors to be arranged in series.

The conveyor includes retaining bases 1A and 1B for retaining a driving roller 2 and a driven roller 3 with a predetermined interval therebetween; the conveyor belt 10 stretched between the driving and driven rollers 2 and 3 for conveying articles; adjusting rollers 7 and 8 movably provided on the retaining bases 1A and 1B halfway between the driving and driven rollers 2 and 3, with a portion of the conveyor belt 10 stretched between the adjusting rollers; and an adjusting screw 9 for adjusting the tension and meandering of the conveyor belt 10 by varying the position of the adjusting roller 7. The members 1A, 1B, 2, 3, 7, 8, 9 and 10 are assembled outside of a machine 31 and then mounted inside the machine 13 after being assembled.