Conservation is the term used for the repair or restoration of anything from pottery to buildings. Restoring a pot from a pile of sherds (or shards, that is, pieces of broken pottery) requires skill and patience but relatively little chemical expertise unless the fabric is painted and the paint is in danger of flaking. The conservation of corroded metalwork requires a knowledge of chemistry and chemical reactions, and techniques tend to be subject to regular improvements. Wall-paintings, textiles, leather, ivories and wood must be kept moist and only allowed to dry out very slowly in proper laboratory conditions or they will discolour, warp or disintegrate. Early accounts of archaeological discoveries are full of references to objects "turning to dust before our very eyes". The restoration of buildings requires considerable architectural expertise, sensitivity as to how much to rebuild and, of course, heavy lifting gear rather than a paint-brush.

Conservation on an archaeological site tends to be a question of first aid so that objects can be brought back to a properly equipped laboratory for treatment. However, it is not always possible to have access to laboratory facilities and the conservator must seek to stabilise the object so that it will not deteriorate. Good packing is essential to avoid the object being broken or affected by changes in temperature or humidity, and this is greatly aided nowadays by the availability of plastic bags and boxes which enable an object to remain visible without its having to be unpacked and handled.