To provide a device and a method for refining and decomposing material composition of mixed pixels in a remote sensing image, capable of achieving space correlation of pixel decomposition results and reducing noise problems caused by isolated decomposition.

The method for refining and decomposing material composition of mixed pixels in a remote sensing image includes: a reception step for receiving a remote sensing image and spectral information corresponding to the image; a preprocessing step for, on the basis of the received remote sensing image and spectral information, temporarily determining a probability value of a composition ratio of each planimetric feature type in each pixel of the image, to obtain first material composition information; and a neighboring area correlation calculation step for analyzing correlation between a main pixel and neighboring areas using the first material composition information of the respective pixels existing in the neighboring areas, within a predetermined range, adjacent to each pixel, and optimizing the first material composition information of the main pixel using the result of the correlation analysis, to obtain second material composition information.