The present invention relates to a closed cartridge (10), for extraction under pressure, comprising a dish (12) with a bottom (13) with a central part and a peripheral part and a side wall having substantially the shape of a frustum of a cone and a circular edge with a diameter greater at the bottom and a cover (15) welded to the periphery of the edge of the dish and the cover is intended to be torn only through the effect of the force of the extraction fluid when extraction starts, the said cartridge comprising, in the dish at the level of the bottom, a means (16) guaranteeing retention of the solid substance when it is opened, in which the means guaranteeing retention of solid substance is a sheet of fabric sealed in the bottom of the dish in two zones, on the one hand in the central part (17) and on the other hand in the peripheral part (18) of the said bottom (13).