To provide an inner stationary planet always existing on a line connecting both centers of gravity of the sun and the earth, and inside the earth orbit.

For example, an inner stationary planet means 3 is placed at a position satisfying the following relation: (Gravity applied on the inner stationary planet means 3 from the sun) =-(Centrifugal force generated when the inner stationary planet means 3 goes around the sun at an angular velocity ω the same as that of the earth) + (Gravity applied on the inner stationary planet means 3 from the earth). This places the inner stationary planet means 3 at a prescribed position between the sun 1 and the earth 2, and the stationary planet means 3 is observed from the earth 2 always stationary in the direction of the sun 1. The stationary planet means 3 can be designed as 'a large parasol' to prevent the earth warming. A solar observing device, a solar power generation device, an earth magnetic field observing device, various types of telescopes and the like can be loaded on the stationary planet means 3. In the same manner, an outer stationary planet 4 placed outside the earth orbit is possible.