Provided is a master controller that can be adopted in a variety of vehicles in which different current capacities are required for the master controller. A master controller includes a handle (3), cams (2a to 2f) interlocking with the handle (3), cam switches (1a to 1f) connected to or disconnected from the cams (2a to 2f) in accordance with the position of the handle (3), and a relay circuit (6) that outputs output signals in accordance with input signals input through the cam switches (1a to 1f).