Provided is a film having excellent heat resistance and a small difference between the permittivity at low temperature and the permittivity at high temperature. The film is characterized in that the relative dielectric constant at a frequency of 1 kHz and 30°C is at least 8, and the rate of change calculated according to the equation below from the relative permittivity A at a frequency of 1 kHz and 30°C and the relative permittivity B at a frequency of 1 kHz and 150°C is -8 to + 8%. Rate of change (%) = (B - A) / A × 100
