To provide a manual drive mechanism for effectively converting human power into motive power, suitable for a vehicle driven by the human power or an apparatus imitated as the vehicle.

Manual drive mechanism units; composed of rotors composed of sprockets provided vertically, a pair of carriers composed of the sprockets, and chains suspended over these rotors and carriers; are fixed to a driving shaft 15, and moreover a chain ring 6 applied by a load is fitted between the rotors 1 and 100 on the driving shaft. In these units, the shaft of a pedal is constituted so as to be vertically held always to the moving surfaces of the respective chains, by a suppressing means composed of free clanks (right unit: 10 and left unit: 1000) and arms (right unit: 11 and left unit: 1100).