A high-energy ion implanter for fabricating a semiconductor device includes a low-energy accelerator for converting a polarity of ions flowed in from an ion source; a stripper for converting the ions accelerated from the low-energy accelerator to positive ions in vacuum conditions; a high-energy accelerator for accelerating, in high-energy, the positive ions that are converted in the stripper; a turbo pump for providing vacuum conditions in the stripper; a current sensor for detecting currents to check for abnormal operating conditions of the turbo pump; and a central processing unit (CPU) that interrupts a circuit breaker to suspend the ion implanting process in response to the level of current detected in the current sensor. The high-energy ion implanter of the present invention is capable of preventing an unsuccessful ion implanting process by suspending operation thereof when abnormal operating conditions are detected.