To provide a curable resin composition excellent in flowability and stress relaxation property which gives an insulating film for circuit boards excellent in wire-embedding performance and connection reliability.

A curable resin composition includes a polymer composition and a curing agent. The polymer composition includes a polymer (A) which is a norbornene-based ring-opened polymer comprising, in a whole repeating unit, ≥51 mol.% of a repeating unit obtained by ring-opening polymerization of a norbornene-based monomer having at least three rings and 1-60 mol.% of a repeating unit having a functional group capable of forming a bond by reaction with the curing agent, or a hydrogenated product thereof; and a polymer (B) which is a norbornene-based ring-opened polymer comprising, in a whole repeating unit, ≥51 mol.% of a repeating unit obtained by ring-opening polymerization of a bicyclic norbornene-based monomer and 1-60 mol.% of a repeating unit having a functional group capable of forming a bond by reaction with the curing agent, or a hydrogenated product thereof.