To provide an obstacle recognizing method and an obstacle recognizing device capable of effectively recognizing obstacles by distinguishing from a wall, or the like.

The device obtains the shape data of a wall surface in a prescribed pitch along a wall surface at a prescribed angle interval in line shape with a laser-type shape sensor 4A, derives an obstacle detecting curve C1 in 3-order polynomial for detecting obstacles in probe range R from the shape data, calculates the error between the obstacle detecting curve C1 and the shape data of the probe range R, separates the places where the error exceeds a threshold value as obstacles such as reinforcing steels projecting from the wall or grooves collapsed from the wall, and thereby recognizes the obstacles.