Cyclic olefin copolymer, and method for producing cyclic olefin copolymer

A cyclic olefin copolymer that is an addition polymer of a cyclic olefin monomer and an α-olefin having 3 or more and 20 or less carbon atoms, wherein

• a ratio of the number of moles of structural units derived from the α-olefin to the number of moles of entire structural units is 10 mol % or more and 50 mol % or less, and
• a one-dimensional scattering curve with respect to a scattering vector q of small angle X-ray scattering for the cyclic olefin copolymer has a primary peak, and a value obtained by dividing a half value width of the primary peak by a q value of a peak top thereof is in a range of 0.15 to 0.45,
• wherein the scattering vector q=(4π sin θ)/λ, π represents the circular constant, 2θ represents the scattering angle, and λ represents the wavelength of incident X-rays.