A fuel supply device for an internal combustion engine, the fuel supply device characterized by comprising: a fuel injection valve; a fuel pressurization device including an electromagnetic valve, the fuel pressurization device being configured to pressurize a fuel in accordance with opening and closing of the electromagnetic valve and discharge the fuel toward the fuel injection valve; and an electronic control unit configured: to control the opening and closing of the electromagnetic valve such that the amount of the fuel discharged toward the fuel injection valve by the fuel pressurization device is adjusted; to execute an operation sound suppression control during a low-load operation of the internal combustion engine, the operation sound suppression control being a control for reducing an opening and closing frequency of the electromagnetic valve and increasing the amount of the fuel discharged by the fuel pressurization device for each opening and closing of the electromagnetic valve; not to execute the operation sound suppression control when a partial lift injection is in progress, the partial lift injection being injection for terminating the fuel injection before a valve body of the fuel injection valve reaches full opening; and to execute the operation sound suppression control when the partial lift injection is not in progress. a fuel injection valve; a fuel pressurization device including an electromagnetic valve, the fuel pressurization device being configured to pressurize a fuel in accordance with opening and closing of the electromagnetic valve and discharge the fuel toward the fuel injection valve; and an electronic control unit configured: to control the opening and closing of the electromagnetic valve such that the amount of the fuel discharged toward the fuel injection valve by the fuel pressurization device is adjusted; to execute an operation sound suppression control during a low-load operation of the internal combustion engine, the operation sound suppression control being a control for reducing an opening and closing frequency of the electromagnetic valve and increasing the amount of the fuel discharged by the fuel pressurization device for each opening and closing of the electromagnetic valve; not to execute the operation sound suppression control when a partial lift injection is in progress, the partial lift injection being injection for terminating the fuel injection before a valve body of the fuel injection valve reaches full opening; and to execute the operation sound suppression control when the partial lift injection is not in progress. to control the opening and closing of the electromagnetic valve such that the amount of the fuel discharged toward the fuel injection valve by the fuel pressurization device is adjusted; to execute an operation sound suppression control during a low-load operation of the internal combustion engine, the operation sound suppression control being a control for reducing an opening and closing frequency of the electromagnetic valve and increasing the amount of the fuel discharged by the fuel pressurization device for each opening and closing of the electromagnetic valve; not to execute the operation sound suppression control when a partial lift injection is in progress, the partial lift injection being injection for terminating the fuel injection before a valve body of the fuel injection valve reaches full opening; and to execute the operation sound suppression control when the partial lift injection is not in progress.