Stability of the spouting in slot-rectangular spouted beds with multiple compartments and slots is investigated and compared with a single-chamber, single-slot spouted bed. Several different configurations of multiple slots were tested, including parallel and aligned, with gas drawn from a common plenum chamber. The stability of the spouting was observed visually and identified by the evolution of pressure drop and its fluctuation. The stability of multiple spouting was found to be mainly affected by the interaction between adjacent fountains and spouts. Stable steady state spouting could be achieved when the chambers were separated by a suspended partition, providing a scale-up method for slot-rectangular spouted beds.