A porous insulating film comprising a highly heat resistant resin film having a fine porous structure with a mean pore size of 0.01-5 nullm in at least the center of the film, and a porosity of 15-80%. A laminate is prepared by forming a heat resistant adhesive layer or a conductive metal layer or an inorganic or metal substrate on one or both sides of the porous insulating film or by forming an inorganic or metal substrate on one side of the porous insulating film and a conductive metal layer on the other side.