PURPOSE: To provide a motor-driven sailboat with a solar battery that sails in use of wind force energy by dint of a motor-driven sail and solar energy by means of the solar battery separately or simultaneously.

CONSTITUTION: As a motor-driven sailboat, sticking a lot of solar batteries 3 to the surface of a motor-driven sail, and being equipped with a wind information detecting means 4, a sunlight detecting means 5, a control part 6 and a sail driving means 7, an energy supply by operation of each solar battery 3 is added to ship propulsion aids by dint of wind force for navigation, and in the case where either of this wind force or sunlight is securable, the energy is effectively used.