PURPOSE: To improve the strength of an inner layer material and to improve dimensional stability by arranging an outer layer material on the outermost layer through a predetermined number of inner layer material surface prepreg layers formed with a circuit on one or both side surface metal-plated laminated board made of triangular woven cloth as its base material.
CONSTITUTION: A laminate in which copper foils are arranged on upper and lower surfaces of seven laminated resin-impregnated cloths obtained by impregnating triangular woven glass fabric with a predetermined amount of epoxy resin containing curing agent and drying it, is laminated under predetermined pressure at a predetermined temperature as a both-side copper-plated laminated board. Electric circuits are formed on both side surfaces of the laminate as inner layer materials. Then, a laminate in which copper foils are arranged on the outermost layers of the upper and lower surfaces of the inner layer material through two epoxy resin-impregnated glass cloth prepregs of predetermined resin amount, is laminated under predetermined pressure at a predetermined temperature as a 4-layer circuit printed board. Thus, its strength, dimensional stability can be improved.