The invention relates to a high-hardness palladium alloy for manufacturing semi-finished products to be used in goldsmith's art or jewels to be obtained by the lost wax casting method, which comprises, in the following concentrations, expressed in thousandths by weight (‰): palladium from 948 to 990‰; copper from 0.0 to 50‰; indium from 0.0 to 50‰; gallium from 1 to 48‰; aluminium from 0.8 to 49.5‰; ruthenium from 0.0 to 50‰; rhenium from 0.0 to 50‰; silicon from 0.1 to 1.2‰; platinum from 0.0 to 40‰; nickel from 0.0 to 50‰; iridium from 0.0 to 40‰. In the manufacturing process of the above alloy, the component elements of said alloy are placed in a crucible, respectively made of zirconia, boron nitride or other ceramic material, and are melted using the induction method and using a protective atmosphere, respectively of argon, nitrogen or other inert gas.