A hydrocracking process that includes a wax fraction hydrocracking step of hydrocracking the wax fraction contained within a Fischer-Tropsch synthetic oil to obtain a hydrocracked product, a gas-liquid separation step of using a multi-stage gas-liquid separator to separate the hydrocracked product into a gas component, a heavy oil component and a light oil component, a specific component content estimation step of determining the flow rate ratio between the heavy oil component and the light oil component, and using this flow rate ratio to determine an estimated value for the content of a specific hydrocarbon component contained within the hydrocracked product, and a control step of controlling the operation of the wax fraction hydrocracking step on the basis of this estimated value, so that the content of the specific hydrocarbon component falls within a predetermined range.