A crossover measuring device comprising: a crossover line sensor adapted to be installed on a roof of a vehicle to look up a crossover; a pantograph line sensor adapted to be installed on the roof of the vehicle to direct against a periphery of t.h-e pantograph; an illuminating member (4, 5) adapted to be installed on the roof of the vehicle to illuminate the crossover; a line sensor image forming section to form line sensor images respectively by lining up, in time series, luminance signals obtained by the crossover line sensor and the pantograph line sensor, and to store as input images; a crossover part height calculating section, characterized in that the crossover part height calculating section is adapted to determine a width of the crossover part on the image from a distance of the edges of the crossover part which are sensed by the crossover part edge sensing section, and to determine a height of the crossover from a lens focal length, a number of pixels of the sensor of the crossover line sensor, and an image resolving power based on a size data of the crossover; and in that the crossover measuring device further comprises: a discrimination analysis binarizing section to form a binary line sensor image in which the crossover part is emphasized by a discrimination analysis binarization of the line sensor image formed by the line sensor image forming section; a noise removing section to remove the noise of the binary line sensor image to which the discrimination analysis binarization is performed by the discrimination analysis binarizing section; a crossover part edge detecting section to detect edges of the crossover part in the binary line sensor image from which the noise is removed by the noise removing section; a crossover part deviation calculating section to determine a value of a center of the edges of the crossover which are sensed by the crossover edge sensing section, as a center of gravity of the crossover, and to determine a deviation of the center of the gravity from a center, based on the center of the gravity of the crossover, the installation position of the crossover line sensor, the lens focal length, the sensor width, the number of the pixels of the sensor, and the height of the crossover which is determined by the crossover part height calculating section; a pantograph height and position calculating section to determine a height and a position of the pantograph based on the binary line sensor image from which the noise is removed by the noise removing section, and a design data of the pantograph; and a pantograph and crossover relative position calculating section to determine a relative position between the pantograph and the crossover, based on the height of the crossover which is determined by the crossover part height calculating section, the deviation of the center of the gravity from the center which is determined by the crossover part deviation calculating section, and the height and the position of the pantograph which are determined by the pantograph height and position calculating section. a crossover line sensor adapted to be installed on a roof of a vehicle to look up a crossover; a pantograph line sensor adapted to be installed on the roof of the vehicle to direct against a periphery of t.h-e pantograph; an illuminating member (4, 5) adapted to be installed on the roof of the vehicle to illuminate the crossover; a line sensor image forming section to form line sensor images respectively by lining up, in time series, luminance signals obtained by the crossover line sensor and the pantograph line sensor, and to store as input images; a crossover part height calculating section, characterized in that a discrimination analysis binarizing section to form a binary line sensor image in which the crossover part is emphasized by a discrimination analysis binarization of the line sensor image formed by the line sensor image forming section; a noise removing section to remove the noise of the binary line sensor image to which the discrimination analysis binarization is performed by the discrimination analysis binarizing section; a crossover part edge detecting section to detect edges of the crossover part in the binary line sensor image from which the noise is removed by the noise removing section; a crossover part deviation calculating section to determine a value of a center of the edges of the crossover which are sensed by the crossover edge sensing section, as a center of gravity of the crossover, and to determine a deviation of the center of the gravity from a center, based on the center of the gravity of the crossover, the installation position of the crossover line sensor, the lens focal length, the sensor width, the number of the pixels of the sensor, and the height of the crossover which is determined by the crossover part height calculating section; a pantograph height and position calculating section to determine a height and a position of the pantograph based on the binary line sensor image from which the noise is removed by the noise removing section, and a design data of the pantograph; and a pantograph and crossover relative position calculating section to determine a relative position between the pantograph and the crossover, based on the height of the crossover which is determined by the crossover part height calculating section, the deviation of the center of the gravity from the center which is determined by the crossover part deviation calculating section, and the height and the position of the pantograph which are determined by the pantograph height and position calculating section.