The present invention provides a resin product comprising: an active ingredient; a thermoplastic resin (2) having a melting enthalpy (”H) of 30 J/g or more, as observed by differential scanning calorimetry within a temperature range of 10°C or more and less than 60°C; and a thermoplastic resin (3) having a storage elastic modulus E' at 60°C of 5.0 × 10 5 Pa or more, as determined by dynamic viscoelasticity measurement at a frequency of 10 Hz. The present invention also provides a molded article comprising the resin product and a device for sustained-release of an active ingredient comprising a component consisting of the resin product.