A dielectric welding film capable of achieving a tight welding through a short period of dielectric heating, and a welding method using the dielectric welding film are provided. The dielectric welding film is configured to weld a pair of adherends of the same material or different materials through dielectric heating, the dielectric welding film including a thermoplastic resin as an A component and a dielectric filler as a B component and satisfying the conditions (i) and (ii): (i) a melting point or softening point measured in accordance with JIS K 7121 (1987) is in a range from 80 to 200 degrees C.; and (ii) heat of fusion measured in accordance with JIS K 7121 (1987) is in a range from 1 to 80 J/g.