A road surface condition estimation apparatus (1) is provided with a collecting device (111) for collecting, from vehicle (2), behavior information relating to a behavior of the vehicle; a determining device (112) for determining on the basis of the behavior information whether or not an abnormality condition is satisfied, the abnormality condition being set on the basis of a specific behavior that is expected to be taken by the vehicle when the vehicle encounters a road surface abnormality; and an estimating device (112) for estimating a condition of the road surface on the basis of a determined result of the determining device.