PURPOSE: To generate larger electric power by constituting so that a protective sheet used at the time of launching a solar battery array may be used as a condenser of sunbeams after the solar battery array is developed.

CONSTITUTION: A blanket 1 and a condenser 2 serving also as a protective sheet are laminated and turned up in a waveform, and folded in a strip shape to be housed between two pressing plates 3. This folding state is held by lower portions of the two pressing plates by means of a first extending rod 5. When a solar battery array is launched into a space and reaches a specified position, the first extending rod 5 is driven by an exterior command to develop the blanket 1 and the condenser 2 serving as a protective sheet in the longitudinal direction into a plane shape. Then, a second extending rod 6 is extended to slide the condenser 2 serving as a protective sheet in the width direction so as to expose a beam receiving surface of a solar battery cell 7, and thereafter a hoisting part, 14 is operated to lift a free end of the condenser 2 serving as a protective sheet upward so as to operate as a condenser.