To provide a jig damage preventive mechanism which can avoid damage of a jig by collision with other member, during moving of the jig.

Slopes 3b, 5b1, 5b2, and 13b are provided on the respective surfaces near the adjacent part of standard direction guides (feeder side guides) 3 and 13, and a direction change guide (receiver side guide) 5 to increase the widths of jig passing grooves 2, 4 and 12 near the adjacent part of the respective guides 3, 5, and 13, thereby the collision of a jig 1 with the guides 5 and 13 on the receiver side is prevented, even when a position slippage is generated in the guides 3, 5 and 13.