PURPOSE: To improve heat stability and rigidity at a high temperature, and to increase a cure rate, by adding resol diluted with a plastifiable material evaporable at a molding temperature to a novolak-type phenolic resin molding material.

CONSTITUTION: 100 parts by wt. of a molding material compositin consisting mainly of novolak is blended with 1W10 parts by wt of resol diluted with a plastifiable material having a boiling point not higher than 170°C. Methanol, n-butyl alcohol, hexanol, styrene, toluene,water, etc. may be cited as the plastic material. The solid content of the resol diluted with the plastic material is preferably 10W70 wt.%.