The present invention relates to a method and kit of detecting a target material using an aptamer, and more particularly to a method and kit for detecting a target material, in which a sample and a second aptamer are added to a first aptamer immobilized on a solid phase so as to form a bond sandwiched between the first aptamer, the target material and the second aptamer, to an FET sensor-based method and kit for detecting a target material, and to an AAO sensor-based method and kit for detecting a target material.The inventive method for a target material using an aptamer can detect even low-molecular-weight materials which were difficult to detect in the prior art, thereby enabling detection of disease-related metabolites, environmental pollutants and food toxins in solutions. In addition, the detection method of the present invention is a direct and simple method and is highly cost-effective, because it uses the aptamer which can be consistently reproduced and can be produced at low costs. Thus, the present invention is very useful.