The invention provides a traveling road surface detection device and a traveling road surface detection method capable of accurately detecting a road surface on which a vehicle can travel. An area specification unit (22A) specifies a road surface area, a stereoscopic object area, a road surface area, and an indeterminate area based on a parallax image. A parallax height specification unit (22D) specifies, as a parallax height area, an area including a parallax point with a height equal to or greater than a threshold value, the threshold value determined in advance from a height of a road surface in the indeterminate area. A traveling road surface detection unit (22B) detects a traveling road surface that sequentially extends in a direction away from a vehicle V on a captured image. Furthermore, the traveling road surface detection unit (22B) does not detect, as a traveling road surface, any of the stereoscopic object area, the parallax height area and an area on the far side of the stereoscopic object area and the parallax height area from the vehicle V.