Different scanning force techniques and specially selected probes were employed to examine the nanofibrillar structure of gel-drawn ultra high molecular weight polyethylene. In order to avoid image artifacts and observe details of the surface structure with an improved resolution, the quality of probes was controlled with a new calibration gauge. Images recorded in the lateral force and tapping modes showed more structural features than those obtained in the normal force mode. Particularly a regular striped pattern was detected on the surface of nanofibrils. According to its repeating distance, ca.25 nm, this pattern is consistent with the long period of UHMW PE observed earlier by SAXS and TEM.