A motion vector estimating device estimating a motion vector having high accuracy is provided. An eliminating unit eliminates each of pictures in a set of input pictures for each picture. A picture reducing unit reduces left pictures after the elimination, and generates reduced pictures. An overall motion vector estimating unit reads the reduced pictures, stored in the frame memory, as either reduced inputted pictures or reduced reference pictures, and estimates an overall motion vector between reduced pictures. Based on the overall motion vector estimated between the reduced pictures, a correction motion vector calculating unit calculates a motion vector between two reduced pictures as a correction motion vector. The correction motion vector calculating unit calculates the motion vector in the order of the inputted pictures in a pre-eliminated set of input pictures. A coding unit estimates the motion vector for each macroblock, using a determined search range, and performs cording processing.