Noncontact high-resolution imaging was succeeded in air by detecting a phase change of the quartz resonator, which made it possible to measure an attractive force gradient with high-quality factor even in air. The distance between a tip and a sample was controlled under the phase change of about -0.1 degrees induced by attractive force gradient acting on the tip. A vertical and a lateral resolutions of 1 and 100 Angstrom, respectively, were obtained in noncontact imaging, respectively.