A prepreg, for printed wiring boards, comprising a flame resistant resin composition containing a specific cyanate ester resin, a nonhalogen epoxy resin, boehmite which is hardly soluble in acids or alkalis and a silicone powder which is a flame retardant assistant, and a base material, which prepreg retains high-degree flame resistance without a halogen compound and has excellent resistance to chemical, high glass transition temperature, excellent soldering heat resistance and excellent heat resistance after moisture absorption, and a laminate or metal-foil-clad laminate obtained by curing the above prepreg.