An object of the present invention is to provide a thermosetting resin composition having high heat resistance, high flame retardancy, good mechanical properties, and high dimensional stability. To achieve the object, there are provided a thermosetting resin composition containing a polyimide resin and a boron compound represented by general formula below and a cured product of the thermosetting resin composition. (R1's each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. R2's each independently represent hydrogen, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Y represents a nitrogen-containing heterocyclic compound. R3's each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Z represents a nitrogen-containing heterocyclic compound.)