Fe-6.5%Si alloy spray formed has the Curie temperature variation measured as a function of the parameters process. In this work the magnetic transition temperature was obtained by Differential Scanning Calorimeter although it can be also gotten by Vibration Samples Magnetometer. The process parameters controlled were gas pressure (P), tube diameter (T) and fly height (H) and the properties analyzed were coercive force, maximum permeability, power loss and Curie temperature. The chemical composition was determined using the Curie temperature. The microstructure of deposits was observed in different conditions of light microscopy, bright field, polarized light and dark field, and the grain size was measured according to ASTM 112-95. The process parameters combination P5T6H360 has produced the minimum power loss of 2.26 W/kg and maximum permeability of 9,000. The Curie temperature measured was 683°C, which indicates a Si content of 6.5wt%.