A trolley wire measurement apparatus for a car, comprising: a first and a second trolley wire measuring means (2, 3), both of which are configured to be provided on a roof of a car, and to project slit laser beams (L1, L2), approximately in a vertical direction, upon a trolley wire from a lower left-hand side and a lower right-hand side thereof, so as to be irradiated on said trolley wire; thereby obtaining images (a1, b1), presenting configurations of said trolley wire on the lower left-hand side and the lower right-hand side thereof, including a side surface thereof, each being obtained from an image (a1, b1) of the reflection light of said projected laser beams (L1, L2), respectively; wherein each of said first and said second trolley wire measuring means (2, 3) is constructed with a light projecting means (2a, 3a) for projecting said laser beam (L1, L2) upon said trolley wire, approximately in the vertical direction, and a light receiving means (2c, 3c) for photographing said image (a1, b1) with a predetermined elevation angle directing to the progress of said car; and wherein the trolley wire measurement apparatus further comprises: a laser length measuring sensor means, which is configured to be provided in the vicinity of a center of the roof of said car, and to scan a laser beam into a direction of deviation of said trolley wire; a height and deviation detecting means, which is configured to detect height and deviation coordinates of said trolley wire on the basis of signals from said laser length measuring sensor means; and a controller means, which is configured to calculate distances of the first trolley wire measuring means on the left-hand side and of the second trolley wire measuring means on the right-hand side to the trolley wire, based on a result of the detection by the trolley wire height and deviation detecting means, wherein the controller means is configured to process the images (a1, b1) presenting the configurations of said trolley wire on the lower left-hand side and the lower right-hand side of said trolley wire, including the side surface thereof, which are obtained by said first and said second trolley wire measuring means (2, 3), wherein the processing comprises adjusting the images (a1, b1), based on the calculated distances, so that the sizes of the images (a1, b1) become equal to each other, thereby producing data indicative of a cross-section configuration of said trolley wire on the sliding surface and the left-hand side and the right-hand side thereof. a first and a second trolley wire measuring means (2, 3), both of which are configured to be provided on a roof of a car, and to project slit laser beams (L1, L2), approximately in a vertical direction, upon a trolley wire from a lower left-hand side and a lower right-hand side thereof, so as to be irradiated on said trolley wire; thereby obtaining images (a1, b1), presenting configurations of said trolley wire on the lower left-hand side and the lower right-hand side thereof, including a side surface thereof, each being obtained from an image (a1, b1) of the reflection light of said projected laser beams (L1, L2), respectively; wherein each of said first and said second trolley wire measuring means (2, 3) is constructed with a light projecting means (2a, 3a) for projecting said laser beam (L1, L2) upon said trolley wire, approximately in the vertical direction, and a light receiving means (2c, 3c) for photographing said image (a1, b1) with a predetermined elevation angle directing to the progress of said car; and wherein the trolley wire measurement apparatus further comprises: a laser length measuring sensor means, which is configured to be provided in the vicinity of a center of the roof of said car, and to scan a laser beam into a direction of deviation of said trolley wire; a height and deviation detecting means, which is configured to detect height and deviation coordinates of said trolley wire on the basis of signals from said laser length measuring sensor means; and a controller means, which is configured to calculate distances of the first trolley wire measuring means on the left-hand side and of the second trolley wire measuring means on the right-hand side to the trolley wire, based on a result of the detection by the trolley wire height and deviation detecting means, a laser length measuring sensor means, which is configured to be provided in the vicinity of a center of the roof of said car, and to scan a laser beam into a direction of deviation of said trolley wire; a height and deviation detecting means, which is configured to detect height and deviation coordinates of said trolley wire on the basis of signals from said laser length measuring sensor means; and a controller means, which is configured to calculate distances of the first trolley wire measuring means on the left-hand side and of the second trolley wire measuring means on the right-hand side to the trolley wire, based on a result of the detection by the trolley wire height and deviation detecting means, wherein the controller means is configured to process the images (a1, b1) presenting the configurations of said trolley wire on the lower left-hand side and the lower right-hand side of said trolley wire, including the side surface thereof, which are obtained by said first and said second trolley wire measuring means (2, 3), wherein the processing comprises adjusting the images (a1, b1), based on the calculated distances, so that the sizes of the images (a1, b1) become equal to each other, thereby producing data indicative of a cross-section configuration of said trolley wire on the sliding surface and the left-hand side and the right-hand side thereof.