[Problem] A simple operation for inserting each elastic member through a guide path is to be attained[Solving Means] A device for installing an elastic member includes a conveying line for continuously conveying sheets (20A, 20B) to be mounted, a feeding device for continuously feeding elasticmembers (26, 28), andaguide (32) for guiding the elastic members (26, 28) fed from the feeding device, to installation positions on the raw materials (20A, 20B) to be mounted on the conveying line. The guide (32) has an upper section (32A) and a lower section (32B) detachably attached to the upper section (32A). A guide path (32X) whose surrounding is closed is formed between the upper section (32A) and the lower section (32B). The elastic members (26, 28) are guided to the installation positions through the guide path (32X).