PURPOSE: To prevent the possibility of breakage of guide pins by providing each guide trolley with a pin hole in which a guide pin in the lowered position is fitted, and by constituting a dolly driving means so that a driving force is given to the dolly via parts other than the guide pin.

CONSTITUTION: When a dolly 1 is set to a dolly traveling route for driving, a pair of front and rear guide pins 5, 6 on the dolly 1 side are lowered so as to be fitted in the pin holes of respective guide trolleys 31, 32. As a result, the dolly 1 is brought into such a state that it can be moved only along the guide rail 30 for guiding a pair of front and rear guide trolleys 31, 32. By driving the dolly 1 by means of a dolly driving means in this state, articles to be transferred on the dolly 1 are transferred along a prescribed route. In this case, a pair of front and rear guide trolleys 31, 32 receive a thrust force from a pair of front and rear guide pins 5, 6 on the dolly 1 side, and travel integrally with the dolly 1 along the guide rail 30 for regulating the traveling direction of the dolly 1, thus meandering of the dolly 1 in the right and left directions can be prevented.