PURPOSE: To answer the request of the large electric power formation, realize the simple handling, and accelerate the reduction of dimension and weight by installing a switch means for controlling the generated electric power of a solar battery panel by separating and connecting a part of a plurality of solar battery cells.

CONSTITUTION: Switches 7 and 8 for separating and connecting loads for solar battery cells 11-12 are connected with a solar battery circuit, and the generated electric power of a solar battery panel 2 is controlled by ON/OFF selection- controlling the switches 7 and 8. Accordingly, in the initial state where the deterioration of the solar battery panel 2 is little, the solar battery cells 11-12, are separated by turning OFF the switches 7 and 8, and the generated electric power is set small, while in the end state, all the solar battery cell rows 11-1n are connection-arranged by turning ON the switches 7 and 8, and the generated electric power of the solar battery panel 2 is set max. Accordingly, the generated electric power can be effectively utilized for a long period without increasing the electric power generating capacity of the solar battery panel 2.