A cartridge (10) containing a dose (12) of at least one substance for preparing a liquid product, e.g., coffee, by means of liquid and/or steam introduced into the cartridge (10). The cartridge comprises a body (14) containing the aforesaid dose (12), with a bottom wall (142), through which the liquid product is able to flow out of the cartridge (10), and a cover (16) that closes the body of the cartridge (10) at the end of the body opposite to the bottom wall (142). The body (14) comprises a crushed-plant-fibre material (e.g., with a base of rice husk), which may also be used for producing the cover. Alternatively, the cover (16) may be made of paper material (e.g., filter paper). The body (14) and the cover (16) are connected together via purely mechanical connection, it thus being possible to avoid gluing or welding.