The conditioner, to process animal fodder and human foodstuffs by a mixer with a dwell time for thermal or hydrothermal treatment, has at least one lower dwell unit (4) under the mixer (3) and an upper material dosing feed (2). The dwell unit and the mixer have identical end plates (5,6), which are linked together at least at one end. Hot air is fed into the dwell unit as steam during the dwell time.