A method of testing a semiconductor device including applying a reference test pattern to the semiconductor device in which a preset number of power pins of the semiconductor device are supplied with current, incrementally disconnecting the power pins from the current to set a number of removal power pins, and determining a final number of power pins which represents a minimum number of power pins with which the semiconductor device operates normally. The method additionally includes applying a delay test pattern to the semiconductor device to set a cycle of the delay test pattern corresponding to the number of removal power pins to reduce or prevent an overkill phenomenon.