To provide a desirable manufacturing method of a form panel incorporated with a reinforcing metallic core.

In this insulating form panel, the waveform reinforcing metallic core is incorporated into a body made of an insulating foam, the waveform metallic core has substantially the same height as the foam, and exteds in the foam over the total length. The foam has a T-shaped bar. This manufacturing method of the insulating form panel is a method having a process of manufacturing the metallic core forming a shape of a metallic core band, a process of supplying the metallic core band on a main conveyor, a process of preparing a mixture for making the insulating foam, a process of continuously injecting the mixture at an entrance of the main conveyor, a compression process of compressing the foam expanding along the main conveyor while forming so as to shape a continuous body band incorporated with the continuous metallic core band and a process of cutting the continuous body band and the continuous metallic core band incorporated into this band at a specific length at an exit of the main conveyor.