To obtain an adhesive which has adhesiveness, solder heat resistance, nonhalogen flame retardance, electrolytic corrosion, resistance to moist heat necessary for a printed wiring board such as a glass epoxy substrate, a flexible substrate, and to prepare an adhesive film.

The flame-retardant adhesive is obtained by mixing 100 pts.wt. of a mixture comprising 50-89 wt.% of an acrylic resin which is obtained by polymerizing (A) an epoxy group-containing (meth)acrylate monomer with (B) acrylonitrile and (C) another polymerizable monomer and has 500,000-1,000,000 weight-average molecular weight and -30°C to -10°C glass transition temperature, 10-30 wt.% of an epoxy resin and 1-10 wt.% of a curing agent with 35-65 pts.wt. of a metal hydroxide. The adhesive film is obtained by forming an adhesive layer using the flame-retardant adhesive.