PURPOSE: To aim at preventing the clingy jam of a consistent load at the point midway in a conveyance, by setting the critical surface tension of a cover layer of a conveyor belt for consistent load conveyance use to the lower point than that of a conveying load, while setting the tension of a head snap pulley to the higher point than the conveying load.

CONSTITUTION: When the critical surface tension of a conveying load is set down to a force unit of A dyne/cm, these ones that surface tension in a cover layer of a conveyor belt 1 is below A-15 dyne/cm or A+15 dyne/cm in case of a head snap pulley otherwise are used and combined with each other. To set the surface tension of the cover layer of the conveyor belt 1 to the point less than A-15 dyne/cm, it will do merely that silicone rubber is applied to the adhesive rubber of a core cord and canvas and unified together as one body. Likewise, to set the surface tension of the head snap pulley 4 to 20-40 dyne/cm, it also will do merely that the surface of the pulley is covered with isobutylene-isoprene rubber and chloroprene rubber or the periphery of the pulley 4 is as well covered with a blended body of these rubber components. With this, stable operation can be achieved without any trouble there for a long period of time.