The ever growing trend towards miniaturisation means that manufacturing technology has to change from using routine engineering to nanometre scale metrology and beyond. Some of the implications of this will be discussed. Central to this change is the development, operation and properties of scanning probe microscopes and in particular the atomic force microscope. The nature and integrity of what these instruments reveal will be investigated and will be related to traditional measurements. The discussion will suggest that the major problem is still the quantitative understanding of the interaction between the sample and the probe. Also, it will be demonstrated that a new requirement is the need to more closely interlock macro- and nanometrology in order to cater for the exact specifications of the freeform geometrical components now emerging to meet the future engineering and physical challenges. Background is given where appropriate.