The new developed method for pressure measurement into the decomposition crack betweenthe melt and the pattern off ers new possibilities for the monitoring of the mold fi lling in thelost foam process. Necessary for this measurement are very sensitive load cells for the smallpressure ranges. The measurements show the kinetics of the foam pattern decomposition, thevariations of the pressure are a reference to turbulent current of the mold. Furthermore it ispossible that the variations can be avoided through a goal-oriented fi lling velocity of the meltin accordance with the pattern geometry. The developed method is convenient for the low pressurelost foam process.