To provide an improved electrical control unit of a motor-driven derailleur for a bicycle superior in ergonomics, simple in structure, and more functional in comparison with a device by prior art.

The electrical control unit is composed of a support body 12 provided with a fixing means to a handle bar 14 of the bicycle, a brake control lever 16 hinged to the support body 12, a pair of electric switches 24 and 26 provided on the support body 12 or controlling gear change, and a manually operable gear change lever 38 for controlling one of the switches 24 and 26. The gear change lever 38 is composed of a first portion 40 coupled to the support body 12 so that the gear change lever 38 can be shifted between a resting position and an operating position, and a second portion 44 hinged to the first portion 40.