Abstract: The device according to the invention intended for chemical analyses comprises a continuous sheet with at least two segments (6,8 or 30,31). The first one of the segments (6 or 30) contains a site (13 or 35) on which at least one of the reagents is present from the beginning and on which the contact between sample and reagent can take place. A second segment (8 or 31) contains a site (17 or 39) on which the presence of detectable substance can be shown. The first and other segments (6 and 8 or 30 and 31) are foldable in such a way that the site (13 or 35) with the reagent can be brought to overlap the site (17 or 39) for detection. The device also includes at least one arrangement (7 or 48) for the separation of reagent that has not reacted during the contact between sample and reagent. This arrangement is activated before the presence of detectable substance is shown. The segments are foldable in such a way that the desired segments can overlap each other for performing the desired analytical steps.