Provided is a curable compound having a low melting temperature, having excellent workability as a result of having good solvent solubility, and being capable of forming a cured product having excellent heat resistance. The curable compound according to an embodiment of the present invention includes the following characteristics (a) to (e). (a) Number average molecular weight (calibrated with polystyrene standard): 1000 to 15000. (b) Proportion of a structure derived from an aromatic ring in the total amount of the curable compound: 50 wt. % or greater. (c) Solvent solubility at 25° C.: 1 g/100 g or greater. (d) Glass transition temperature: 280° C. or lower. (e) 5% Weight loss temperature (Td5) measured at a rate of temperature increase of 10° C./min (in nitrogen), for a cured product of the curable compound: 300° C. or higher.