In this paper, a novel stacked differential mode rectenna is proposed and its characteristics are experimentally evaluated. The proposed rectenna operates in a differential mode. Therefore, the proposed rectenna can effectively rectify microwave power even under low power environments. The conversion efficiency of 37.1% was obtained when the received power density was as low as 0.04 W/m2. The proposed rectenna can easily achieve large-scale rectenna arrays by simply stacking the rectifying diodes and microstrip antennas because the stacking structure does not degrade the conversion efficiency.