A curable resin composition which comprising (A), (B) and (C) as follows: (A) 100 parts by mass of polyfunctional epoxy component which contains (A1) a trifunctional epoxy compound having three glycidyl groups in a molecule and (A2) a tetrafunctional epoxy compound having four glycidyl groups in a molecule, wherein (A1):(A2) is 10:90 to 90:10 in terms of mass; (B) 25 to 200 parts by mass of a cyanic acid ester compound having two or more of cyanato groups; and (C) 0.5 to 20 parts by mass of an imidazole compound as a curing agent.