An implantable device that includes a plurality of conduits, a plurality of chambers, and a control unit. The blood through the plurality of conduits and the chambers collect the ingredient information of the blood according to the blood through the conduits. The chambers transfer the ingredient information of the blood to the control unit to analysis. The chamber includes two electrodes, the chamber exploits a reverse theorem to force the glucose of the blood generates a plurality of charges flowing between the electrodes and further to generate a current in the chamber. Thus, the implantable device can achieve the goal of the self-electricity-generation.