An inclination detection apparatus detects the inclination of a mobile body with three marker rods having different inclinations with respect to one another. The mobile body is provided with a laser range finder irradiating surrounding objects with a laser beam to light a point on each of the three marker rods as a reflection point from which the laser beam is reflected back. The inclination detection apparatus includes a processor and a storage device storing relative positional information of the three marker rods. The processor obtains positional information of reflection points, obtains relative positions of the reflection points on the three marker rods by determining points on the three marker rods corresponding to the obtained positional information based on the relative positional information of the three marker rods, and identifies an inclination plane including the obtained relative positions of the reflection points as the inclination of the mobile body.
