There are provided an environment recognition device and an environment recognition method. The device obtains luminances of a target portion in a detection area, assigns a color identifier to the target portion according to the luminances thereof based on an association, retained in a data retaining unit, between a color identifier and a luminance range, groups target portions, of which position differences in the width and height directions are within a predetermined range and to which one or more color identifiers corresponding to a same specific object are assigned, into a target object, based on a association, retained in the unit, between a specific object and the color identifier; and determines an outer edge specified by the target portions to which the color identifiers are assigned according to whether or not the detection area is in the environment where light is diffused, as the outer edge of the target object.