A novel exploration method of ocean floor resources is expected for effective utilization of the ocean and the object area for the development expands to deeper sea area recently. An autonomous underwater glider which equips an OBEM (Ocean Bottom Electromagnetometer) for ocean floor resources explorations is proposed in this report. The autonomous vehicle has an ability to achieve a long term continuous resources exploration autonomously. The buoyancy and attitude control mechanism enable the vehicle to move to the next measurement point by gliding. The landing point for the measurement is precisely controlled by the motion control system. The gliding performance of the vehicle is investigated by tank and field experiments. The mathematical model of the vehicle motion is refined based on the study and numerical calculations are carried out to design the motion control system for the autonomous underwater glider for OBEM measurement.