A process for measuring the mercury concentration within a hydrocarbon is provided that enables the mercury concentration to be measured simply and quickly, and with good reliability and good reproducibility. A process for measuring the mercury concentration within a hydrocarbon includes the steps of placing and weighing the hydrocarbon in a sample boat 12 containing an adsorbent that contains a metal capable of forming an amalgam with mercury, and heating the hydrocarbon inside the sample boat 12 in a combustion furnace 13, together with the adsorbent, and measuring the quantity of mercury within the thus generated gas.