A pantograph comprising, as a premise that width and height directions of a car are a y-axis direction and a z-direction, respectively, - a collector shoe having a slider longitudinal in the y-axis direction, which collects electric currents by coming into sliding contact with overhead wires, and a shoe body supporting the slider, and a shoe supporting member supporting the collector shoe at a center part in the y-direction of the collector shoe; - a framework which has upper and lower frames (41, 42) bendable and stretchable in the z-axis direction and supports the shoe supporting member at an end of the upper frame; - an underframe supporting the framework; - a first balancing link constantly holding postures of the collector shoe by screwing an upper end of the first balancing link with the shoe supporting member and by screwing a lower end of the first balancing link with an upper end of the lower frame; - a second balancing link causing the upper frame to swing in respect to swinging of the lower frame by screwing an upper end of the second balancing link with a lower end of the upper frame and by screwing a lower end of the second balancing link with the underframe; and - an automatic descending device having an air tube connected with an air duct and supplying air in the air duct, which automatically descends the collector shoe by bending the framework on the underframe when an inner air pressure in the air duct is equal to or under a prescribed pressure; characterized in that: - the air duct is provided in the slider; - the upper and lower frames (41, 42) of the framework are made of a hollow member; and - the air tube is connected with the air duct in a center part in the y-axis direction of the slider and is inserted into the upper and lower frames (41, 42) of the framework via the shoe supporting member. - a collector shoe having a slider longitudinal in the y-axis direction, which collects electric currents by coming into sliding contact with overhead wires, and a shoe body supporting the slider, and a shoe supporting member supporting the collector shoe at a center part in the y-direction of the collector shoe; - a framework which has upper and lower frames (41, 42) bendable and stretchable in the z-axis direction and supports the shoe supporting member at an end of the upper frame; - an underframe supporting the framework; - a first balancing link constantly holding postures of the collector shoe by screwing an upper end of the first balancing link with the shoe supporting member and by screwing a lower end of the first balancing link with an upper end of the lower frame; - a second balancing link causing the upper frame to swing in respect to swinging of the lower frame by screwing an upper end of the second balancing link with a lower end of the upper frame and by screwing a lower end of the second balancing link with the underframe; and - an automatic descending device having an air tube connected with an air duct and supplying air in the air duct, which automatically descends the collector shoe by bending the framework on the underframe when an inner air pressure in the air duct is equal to or under a prescribed pressure; - the air duct is provided in the slider; - the upper and lower frames (41, 42) of the framework are made of a hollow member; and - the air tube is connected with the air duct in a center part in the y-axis direction of the slider and is inserted into the upper and lower frames (41, 42) of the framework via the shoe supporting member.