A cartridge containing a single serving of a particulate substance extractable by means of water for preparing a beverage, preferably an espresso coffee beverage is disclosed. Between the bottom of the cartridge and the particulate substance as well as between the particulate substance and the cover of the cartridge, in each case a fluid director member is provided, having a plurality of small openings. The one close to the cover serves as a water distribution member for distributing the water, fed into the cartridge through a central opening pierced therein, evenly over the particulate substance, and the one close to the bottom serves as a beverage collection member to lead the beverage to a central opening pierced into the bottom of the cartridge. Both director members are provided with a recess directed towards the interior of the cartridge, allowing the penetration of a piercing member without damage to the director members.