The invention relates to a double-chamber beaker made from plastic or another material, in particular for storing and mixing a two-component product, which double-chamber beaker has a main chamber and an auxiliary chamber which are kept airtight and separate from one another by means of a detachable covering diaphragm and sealing edges and have to be mixed together before application. The auxiliary chamber (4) encloses the main chamber (3) completely, wherein an auxiliary sealing edge (10) is arranged between the main chamber (3) and the auxiliary chamber (4), which auxiliary sealing edge (10) is arranged either higher or lower than the main sealing edge (9) which corresponds with it, or is situated in the same plane, wherein the covering diaphragm (11) forms an airtight auxiliary seal (13) together with the auxiliary sealing edge (10) or can be expediently pressed against the sealing lip (40), in which double-chamber beaker the main seal (12) is to be formed under a prestress, and wherein the product removal takes place without a build-up of pressure and by removal of the covering diaphragm (11) from the double-chamber beaker (1).