PURPOSE: To save the wrapping cost and the like by producing and transporting bow window unit members in a prescribed mounting state and supply the bow window unit members of high precision in the dimension without being deformed during transportation and the like.

CONSTITUTION: A reversed T-shaped jig body 3 formed of a lower frame 1 and a vertical frame 2 is arranged on both the righthand and the lefthand in parallel spaced by a prescribed distance therebetween. An upper joint 4 is placed to bridge between the ends of the vertical frames 2 of the right and left jig bodies 3, while a lower joint 5 is placed to bridge between the lower ends of the lower frames 1 of the jig bodies 3. For enabling an adjustment of a distance between the pair of jig bodies 3, the ends of the upper joint 4 and the lower joint 5 are connected to the jig bodies detachably. In the vertical frame 2 of the jig body 3, a number of mounting holes 7 are pierced through which the bow window unit members 6 are mounted. The lower joint 5 is provided with a fork inserting port 8 into which a fork of a forklift can be inserted.