To provide an apparatus and a method for detecting organic molecules, allowing easy determination of the presence or absence of complementary bonds between organic molecules, such as DNA.

The apparatus includes four resistance elements which are connected in a bridge-like manner. At least one of the four resistance elements has a fixation area 20 for organic molecules. Detection elements 11 to 14 change their resistance, depending on the amount of electrostatic charge of the organic molecules fixed on the fixation area.