Problems with the pulse-jet bag filter operation have a direct influence on process plant operation and may result in loss of production time. Therefore, long-term stable operation of the plant is desirable for both the manufacturers and operators. The effects of operating parameters are studied experimentally on filter operation with regeneration between the upper and lower pressure drop limits. Many combinations were identified when the filter operation derailed from stable to unstable operation on changing one of the operating parameters. Filtration velocity, pulse pressure, and the upper limit of pressure drop had the potential of creating instability. A threshold detachment overpressure existed below which the operation led to unstable conditions at a certain filtration velocity and which increased with increasing velocity.