Amorphos metal has very low iron loss and is expected to improve the efficiency of electrical machine such as motors. In general, amorphos cores are thought to be more superior in high speed motors because iron loss increases with frequency and amorphous metal's low iron loss properties are effective in high frequency region. In this report, however, we studied applicability of amorphous cores for low speed axial gap motors and found that the superiority over electric steel 35A300 existed even in low speed motors. We designed the double rotor axial gap motor which the rated output is 750r/min and 2.0N·m and the amorphous core motor shows 3% efficiency superiority over magnetic steel core motor. Also we found that the difference of efficiency gets wider in low torque output.