Abstract: The steering apparatus in which at least part of the transmission lines (L1, L3) which transmit the control quantity of steering from the steering wheel (20, 120, 220) to the rudder (30, 130, 230) is constituted from a steering cable such as wire so as to steer the rudder by transmitting the control quantity of operating the steering wheel to the rudder through reciprocal motion of the transmission line. The assisting force supplying means (70, 170, 270) is additionally installed and the intermediate linkage rod (60, 160, 260) is installed to interpose in the transmission line, with the transmission line (L2) for transmitting the assisting force supplied from the assisting force supplying means being connected to said intermediate linkage rod in addition to the transmission lines described above, so that the intermediate linkage rod is moved back and forth by the sum of the manual force from said steering wheel and the assisting force from the assisting force supplying means, thereby to steer the rudder.