Disclosed is a resin composition which is advantageous not only in that the resin composition can be produced at low cost, but also in that it is unlikely to thermally expand, and a prepreg, a laminate, and a wiring board formed using the resin composition. The resin composition comprises an insulating resin having an aromatic ring, wherein the insulating resin having an aromatic ring has a molecular weight between crosslinking sites of 300 to 1,000 on the stage after the production of the laminate, as determined from an elastic shear modulus of the insulating resin measured at a temperature of Tg or higher.