To assemble multiple parts simultaneously as a multiple laminate and to reduce manufacturing costs precisely and efficiently.

In a conical swirler 10, the contour and interval of a slot 18 scraped on a conical body are composed for arrangement so that they are adapted to a wide range of requests to a fluid flow region and turning strength. In the conical swirler 10, preferably a swirler material is overlapped to the laminate and the laminate is manufactured simultaneously by a wire electric discharge machining method.