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 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 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 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 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 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 of the framework via the shoe supporting member . <EOS>