An energy harvester with a low startup voltage and wide input range is proposed mainly for solar power. In this work, neither any post-fabrication steps nor excessive external assistant components are required to startup the circuit with a low input voltage. Moreover, a voltage detector is proposed for widening the input voltage range. The proposed chip was fabricated by TSMC 0.18μm 1P6M mixed-signal CMOS process, and the chip area is 899μm×837μm. Measured results show that the minimal startup voltage is 155 mV. After startup, the input voltage may range from 20 mV to 1.7 V. The measured power efficiency is up to 92.8%.