Diamond was successfully synthesized using a low pressure, radio frequency (rf), inductively coupled plasma. A source mixture of methanol (CH3OH), hydrogen (H-2), and water vapor (H2O) was introduced into a-reaction chamber through a quartz tube of 12 mm inner diameter. A seven-turn rf coil was mounted on the quartz tube to produce high-density plasma. The Si substrate was located in a downstream region. Diamond formation was carried out with varying mixture ratio of source gases at total pressures of 70-140 mTorr. Diamond crystals exhibiting a well-defined 1332 cm(-1) diamond-Raman peak dan be formed using CH3OH//H-2/H2O mixtures at total pressures below 140 mTorr.