An activation apparatus of a fuel cell stack includes an output cable connecting unit mounted on the frame and connecting a positive output cable of an electric load system to a positive output terminal at one side of the fuel cell stack. A fluid supply pipe connecting unit is mounted on the frame to reciprocate forward and backward with respect to another side of the fuel cell stack. The fluid supply pipe connecting unit connects a negative output cable of the electric load system to a negative output terminal at the other side of the fuel cell stack and connects a fluid supply pipe of a fluid supply system to a manifold of the fuel cell stack.