PURPOSE: To produce a syntactic polyurethane foam molding capable of minimizing the creation of voids due to an organic solvent used for blending a resin by forming the molding with a polyimide resin according to a spray up method.

CONSTITUTION: A polyimide resin diluted with a solvent is blended, mixed with an adequate amount of a microballoon material and the resultant mixture is directly laminated to the mold surface and molded according to a spray up method. A balloon material of glass, silica or phenol is adopted as the microballoon material. When the content of the microballoon material is high, the mold surface after the mold release treatment is coated with at least one or more layers of only the resin to carry out the molding.