Disclosed is a biaxially oriented film for electrical insulation having even better withstand voltage characteristics than before together with excellent film-forming properties. The biaxially oriented film for electrical insulation of the invention is a film that includes a substrate layer containing a crystalline thermoplastic resin as a main component. The substrate layer contains a phenolic stabilizer in an amount of 0.001 wt % or more and 3 wt % or less based on the weight of the substrate layer. The phenolic stabilizer is an alkylenebisamide-type hindered phenol.