To provide a tape which has flexibility and is excellent in electric characteristics by using varnish which has an ultraviolet-curing property and on which viscosity before irradiation is not more than a specific value.

A support body of flexible nonwoven fabric such as glass cloth is impregnated with a solvent of a varnish composition, and after a final coating varnish composition is applied, the varnish composition is hardened by irradiation of ultraviolet rays, and an electric insulating mica containing tape is obtained. The varnish composition has an ultraviolet-curing property in viscosity not more than 350 mPa.s at 20°C by mixing a monomer having a metacrylic ester functional group with oligomer having a a metacrylic ester functional group. Metacrylic aster is reformed by epoxy and polyester groups, and is formed as a polymer having molecular weight of a range of 300 to 1,000,000, and has viscosity not less than 3000 mPa.s at 60°C, and an optimal adhesive property is imparted. A metacrylic acid monomer is a molecule having low molecular weight, and wetting of mica is optimized in viscosity not more than 100 mPa.s at 20°C.