The pressure dependence of the fusion temperature and the fusion volume change of indium has been investigated with the aid of a high-pressure piston-cylinder-type dilatometer up to 400 MPa. From these results, the pressure dependence of the enthalpy of fusion can be calculated via the Clausius-Clapeyron equation. From our results, together with those of other authors, a best value approximation of the pressure dependence of both quantities has been performed, which we would like to suggest as the basis for calibration of high-pressure thermal analysis devices, especially for DTA and DSC apparatus.