This article reports a fabrication of a rectifier based on Hybrid Semiconductor Integrated Circuit (HySIC) technology and microwave wireless power transfer experiment using the fabricated rectifier at 5.8 GHz. The purpose of this study is developing all-wireless sensor network systems in space satellites, reducing the launching costs, and contributing to space technology development. The HySIC rectifier blends the merits of gallium nitride (GaN) Schottky barrier diodes whose resistivity to cosmic rays is high and silicon (Si) matching circuits whose circuit integration process is excellent. The size and RF-DC conversion efficiency of the fabricated HySIC rectifier were 3.9 mm × 9.5 mm and 10.3% with a load of 150 at 5.8 GHz, respectively. A microwave wireless power transfer experiment was conducted at a distance of 0.2 m. The system conversion efficiency, which includes the effects of the HySIC rectifier, transmitting antenna, receiving antenna, cables, and space of 0.2 m, was 0.014%. The microwave wireless power transfer experiment using the HySIC rectifier was demonstrated for the first time in the world.