Currently, Japan's textile industry has been declining because the cheap fiber product of neighboring Asian countries is expanding the market. Therefore, Japan's textile industry differentiates itself by making fancy yarn of fiber products. Fancy yarn has a high added value. We researched the creation of false twist yarn from the fancy yarn. We are considering applying a 1/f fl uctuation to the yarn shape to add high value to the false twist yarn. However, these methods of production and evaluation have not yet been published. Construction of this method is desired. The object of our research is to provide the design materials for making yarn shape fl uctuations possible. We made the yarn shape imaging apparatus capable of shooting from various directions to evaluate the hreedimensional shape of the false twist yarn. As a result, both yarn tension and twist count influence yarn thickness.