NOVELTY - A thermosetting resin composition contains polyimide resin, epoxy resin and phenol resin. The phenol resin is a triazine modified novolak-type phenol resin chosen from condensate (c1) of phenol, triazine and aldehyde, condensate (c2) of triazine and aldehyde, condensate (c3) of phenol and aldehyde, phenol (c4), and triazine (c5). The condensate (c1) in the phenol resin includes structural unit (F). The condensate (c2) in the phenol resin includes structural unit (G). The polyimide resin includes biphenyl skeleton coupled directly to 5-membered ring imide skeleton.    USE - Thermosetting resin composition is used for interlayer adhesive film for printed wiring board (claimed). Uses include but are not limited to voice coil, solar cell, lithium cell, capacitor, electrode binder, separator, transfer belt for copier, fixing belt, underfill and insulation coating material for electric wire.    ADVANTAGE - The thermosetting resin composition has excellent low-temperature meltability, and provides molded product with excellent dimensional stability.    DETAILED DESCRIPTION - A thermosetting resin composition contains polyimide resin, epoxy resin and phenol resin. The phenol resin is a triazine modified novolak-type phenol resin containing phenol, triazine and aldehyde. The novolak-type phenol resin is chosen from condensate (c1) of phenol, triazine and aldehyde, condensate (c2) of triazine and aldehyde, condensate (c3) of phenol and aldehyde, phenol (c4), and triazine (c5). The condensate (c1) in the phenol resin includes structural unit (F) of formula: -D-NH-CH2-NH-. The condensate (c2) in the phenol resin includes structural unit (G) of formula: -D-NH-CH2-E-. The molar ratio of structural unit (G) with respect to structural unit (F) is 1.5 or more. The polyimide resin includes biphenyl skeleton coupled directly to 5-membered ring imide skeleton, and has logarithmic viscosity of 0.2-0.8 dl/g. The content rate of the biphenyl skeleton is 20-45 %mass.    D'=residue of triazine;and    E=phenol residue.    An INDEPENDENT CLAIM is included for interlayer adhesive film.