PURPOSE: To reduce acceleration generated due to gravity slope acting on a micro- gravity environment employment device by making identical the rotating angular velocity of the satellite in the title and the turning angular velocity thereof along an orbit around the earth, and installing a microgravity environment employment part on a specific plane.

CONSTITUTION: The center of gravity of a micro-gravity environment employment satellite 1 is taken as an origin, the velocity direction of the aforesaid center is shown by an x-axis, a directional line drawn between the center of gravity of the earth B and the aforesaid center is shown by a z-axis and a direction normal to the fixed orbit plane of the satellite is shown by a y-axis respectively. In this case, the rotating angular velocity of the satellite and the turning angular velocity thereof on an orbit A around the earth are kept identical. Furthermore, the microgravity environment employment part 8a of a micro-gravity environment employment device 8 is installed on the x-y plane, or at a position nearest the x-y plane among installation positions available in a rack 9 for mounting the micro-gravity environment employment device 8. Also, for obtaining a better effect, the micro gravity environment employment part 8a is installed on the x-axis or at a distance shortest from the x-axis among the installation positions available in the rack 9.