The thermosetting resin composition and the solder resist ink according to the present invention are characterized by comprising: a thermosetting resin (A) comprising (A1) a compound containing an acid anhydride group and/or a carboxyl group and (A2) a compound having a functional group which reacts with (A1) described above and an organic filler (B) containing a phosphorus atom, wherein the organic filler (B) containing a phosphorus atom has an average particle diameter of 50 Êm or less. According to the present invention, capable of being provided at a low cost and a good productivity are an excellent thermosetting resin composition and solder resist ink capable of forming a cured material which achieves an adhesion to a substrate, a low warping property, a flexibility, a plating resistance, a solder heat resistance and a long term reliability as well as a flame retardancy, and a cured material and a protective film which are excellent in the above characteristics. Further, electronic parts having a protective film which is excellent in a flame retardancy and which has a high reliability can be provided.