By a disparity computation unit 21, first, with respect to a block in a bottom row of a first image, a corresponding block within a second image which has a same Y-coordinate as a Y-coordinate of the block and in which an object same as or similar to an object appearing in the block appears is searched for, and, next, in the case of searching for, with respect to a block which is upward in order from the searched block of the first image, a corresponding block within the second image in which an object same as or similar to that of the block appears, the corresponding block within the second image which has a same Y-coordinate as a Y-coordinate of the block of the first image and in which an object same as or similar to that of the block of the first image appears in an X-coordinate setting range with an X-coordinate of the corresponding block of the second image corresponding to the searched block which is immediately below the block of the first image as a center is searched for. Thus, provided is an obstacle detection device capable of simplifying processing for finding an obstacle, shortening a processing time and simplifying a hardware configuration.