A traveling road surface detection device for detecting a road surface on which a vehicle can travel, the traveling road surface detection device comprising: a parallax image generation unit configured to generate, based on a captured image of the surroundings of the vehicle captured by an in-vehicle camera, a parallax image including a parallax point that is a pixel associated with parallax information; an area specification unit configured to set a grid in the captured image and to classify parallax points in the parallax image into a stereoscopic object candidate point, a road surface candidate point and an indetermination candidate point and to: specify a grid square where only a road surface candidate point is present as a road surface area, specify a grid square where only a stereoscopic object candidate point is present as a stereoscopic object area, and specify a grid square where an indetermination candidate point is present as an indeterminate area; a road surface height estimation unit configured to estimate a height of a road surface within the road surface area based on the road surface candidate point in a grid square specified as the road surface area by the area specification unit; and a parallax height specification unit configured to specify, among the one or more grid squares specified as the indeterminate area, one or more grid squares including one or more parallax points with a height equal to or greater than a threshold value, the threshold value determined in advance, as a parallax height area based on the estimated height of the road surface and the parallax information, wherein the height of the one or more parallax points is estimated using the height of a road surface within the road surface area estimated by the road surface height estimation unit as a reference height, and a traveling road surface detection unit configured to detect, based on the grid squares within the captured image, sequentially, from a part of the road surface closest to the vehicle to a part of the road surface furthest from the vehicle, the road surface on which the vehicle can travel as the road surface extends in a direction away from the vehicle with respect to the grid in the captured image; wherein the traveling road surface detection unit is configured not to detect, as the road surface on which the vehicle can travel, 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. a parallax image generation unit configured to generate, based on a captured image of the surroundings of the vehicle captured by an in-vehicle camera, a parallax image including a parallax point that is a pixel associated with parallax information; an area specification unit configured to set a grid in the captured image and to classify parallax points in the parallax image into a stereoscopic object candidate point, a road surface candidate point and an indetermination candidate point and to: specify a grid square where only a road surface candidate point is present as a road surface area, specify a grid square where only a stereoscopic object candidate point is present as a stereoscopic object area, and specify a grid square where an indetermination candidate point is present as an indeterminate area; specify a grid square where only a road surface candidate point is present as a road surface area, specify a grid square where only a stereoscopic object candidate point is present as a stereoscopic object area, and specify a grid square where an indetermination candidate point is present as an indeterminate area; a road surface height estimation unit configured to estimate a height of a road surface within the road surface area based on the road surface candidate point in a grid square specified as the road surface area by the area specification unit; and a parallax height specification unit configured to specify, among the one or more grid squares specified as the indeterminate area, one or more grid squares including one or more parallax points with a height equal to or greater than a threshold value, the threshold value determined in advance, as a parallax height area based on the estimated height of the road surface and the parallax information, wherein the height of the one or more parallax points is estimated using the height of a road surface within the road surface area estimated by the road surface height estimation unit as a reference height, and a traveling road surface detection unit configured to detect, based on the grid squares within the captured image, sequentially, from a part of the road surface closest to the vehicle to a part of the road surface furthest from the vehicle, the road surface on which the vehicle can travel as the road surface extends in a direction away from the vehicle with respect to the grid in the captured image; wherein the traveling road surface detection unit is configured not to detect, as the road surface on which the vehicle can travel, 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.