New imaging technique in AFM has been developed to suppress bending of the probe during scanning. The technique controls the probe such that approaching and gap-controlling are done after only one step xy-scanning is completed (only z-movement is done without scanning), and the xy-scanning is done after lifting the probe up from the sample surface. This technique permits to use very sharpened probe and to observe a steep structure such as a dry-etched groove and a hole, and a photoresist pattern with a high aspect ratio faithfully. It is possible to apply this technique to monitoring the steep structures in the LSI process without cracking the wafer. (C) 2002 Elsevier Science B.V. All rights reserved.