We report on the field emission properties of carbon nanotubes, focusing on current density versus electric field (J-F) characteristics and the spacing between the emitter and collector. We grew carbon nanotubes on SUS304, nickel, Inconel-600, and Invar-42 substrates using plasma-enhanced chemical vapor deposition, using methane gas as the carbon source and hydrogen gas as the catalyst and dilution gas. We found that nanotubes grew fastest on Invar-42. Nanotubes were distributed from 50 to 100 nm in diameter and from 1 to 30 mum long. Onset field of the field emission was 0.7 V/mum and the current density was 1 mA/cm(2) at an electric field of 3.0 V/mum. A Fowler-Nordheim plot was made. Field enhancement factor beta and emission area cc were calculated and compared between substrates. Using nickel on quartz glass, carbon nanotubes were selectively fabricated on metal lines on quartz glass.