A coordinate detecting device includes a detecting unit configured to detect the capacitance of each of a plurality of electrodes which are arranged in a predetermined direction, a storage unit configured to store the detected capacitance of each electrode, and an arithmetic processing unit configured to perform an arithmetic process on the basis of the capacitance of each electrode stored in the storage unit. The detecting unit sequentially detects the capacitance of the plurality of electrodes from one end to the other end of the predetermined direction. The arithmetic processing unit determines a coordinate region of a detection target in the predetermined direction on the basis of a comparison value between capacitance variations of adjacent electrodes and the magnitude of the detected capacitance variation of each electrode.