Provided is a resin composition for an acoustic matching layer, the resin composition including an epoxy resin (A), a specific polyamine compound (B), and metal particles (C). The epoxy resin (A) includes at least one epoxy resin selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and phenol novolac epoxy resins. Also provided are a cured product formed of the composition, an acoustic matching sheet, an acoustic probe, an acoustic measuring apparatus, a method for producing an acoustic probe, and an acoustic matching layer material set.