There are provided an environment recognition device and an environment recognition method. The device obtains position information of a target portion in a detection area, including a relative distance from a subject vehicle; groups continuous target portions into a target object of which position differences in a width direction vertical to an advancing direction of the vehicle and in a depth direction parallel to the advancing direction fall within a first distance; determines that the target object is a candidate of a wall, when the target portions forming the target object forms a tilt surface tilting at a predetermined angle or more with respect to a plane vertical to the advancing direction; and determines that the continuous wall candidates of which position differences in the width and depth directions among the wall candidates fall within a second predetermined distance longer than the first predetermined distance are a wall.