This three-dimensional object detection device is characterized by being provided with: a first three-dimensional object detection means (33) that detects three-dimensional objects on the basis of a captured image a light source detection means (34) that detects light sources present rearwards from the vehicle of the device a second three-dimensional object detection means (35) that detects three-dimensional objects on the basis of the light sources a three-dimensional object determination means (37) that determines whether or not a three-dimensional object is an neighboring vehicle a cloudiness calculation means (38) that calculates a lens cloudiness on the basis of a captured image and a control means (37) that determines whether or not a three-dimensional object is a neighboring vehicle on the basis of the detection results by at least the second three-dimensional object detection means when the lens cloudiness is at least a predetermined determination value, and determines whether or not a three-dimensional object is a neighboring vehicle on the basis of the detection results of at least the first three-dimensional object detection means when the lens cloudiness is less than the determination value.Un dispositivo de detección de objetos tridimensionales provisto con un primer medio (33) de detección de objetos tridimensionales para detectar un objeto tridimensional basado en una imagen capturada, un medio (34) de detección de una fuente de luz para detectar una fuente de luz que está presente detrás de un vehículo anfitrión, un segundo medio (35) de detección de objetos tridimensionales para la detección de un objeto tridimensional basado en la fuente de luz, un medio (37) de evaluación de objetos tridimensionales para evaluar si el objeto tridimensional es un vehículo adyacente, un medio (38) de cálculo de grado de empañamiento para calcular un grado de empañamiento de la lente, y un medio (37) de control para evaluar si el objeto tridimensional es un vehículo
