PURPOSE: To prevent falling of transport ability for a work by moving a pair of arms in the same direction and at the same speed as a work being transported, and performing the positioning and engaging operation of the arms in the condition of transporting the work.

CONSTITUTION: A stationary arm 40 and a movable arm 50 are provided so that the respective extreme ends are opposite to each other, arranged movably along the direction of transporting a work W, and engaged with the work W through the individual extreme end parts. When the extreme end parts of the stationary arm 40 are positioned on the positions corresponding to the transporting territory of the work W, an approaching sensor 83 is operated so as to detect arrival of the transported work W on a decided position against the extreme end part of the stationary arm 40. Based on the detected result of the approaching sensor 83, the stationary arm 40 and the movable arm 50 are moved in the same direction and at the same speed as the work W, and the work W is engaged with the respective extreme end parts during movement of the stationary arm 40 and the movable arm 50.