PURPOSE: To provide the rationalized manufacturing method for a new light- weight composite molded material with good mechanical physical properties compared with its weight.

CONSTITUTION: A fiber web containing foam expansible particles and hollow particles in separate layers is manufactured by heating, and said web is, for instance, put in a mold an heat molded together with resin to manufacture a light composite molded material using a reinforced syntactic foamed layer. A sandwich material composed of a core material of said light-weight molded material and an FRP skin can be manufactured by laminating said web and a reinforced fiber fabric and the like and molding the laminate together with resin at that time.