To provide a pattern retrieval method and a device thereof capable of retrieving at a high speed.

When a pattern is retrieved, an observation image of an image taken in from a digital camera is cut out using a retrieval window by a computer, the observation image is displayed in a liquid crystal space optical modulator of an optical parallel arrangement correlation device by matching with each channel of a binary array optical element, computing is done by the optical parallel arrangement correlation device to generate a correlation signal proportional to a degree of similarity of image, and which reference image is at which position of the observation image is outputted from the intensity of the correlation signal as the result.