Abstract: This invention relates to an automatic staining apparatus for staining many slide specimens such as tissue specimens by dipping them sequentially into a large number of chemical solution containers while they are mounted in a slide holder basket.Conventional automatic staining apparatuses have a problem in the staining efficiency because a basket is attached manually to a clamp member of the apparatus, and also have another problem that remaining chemical solution cannot be sufficiently removed from slide specimens.In order to solve these problems, an automatic staining apparatus according to the first present invention has the clamp member which can automatically engage with, and disengage from a basket, so that the staining efficiency is much improved. Preferred embodiment of the invention has a tilting mechanism for the clamp member, so that chemical solution is sufficiently removed from slide specimens.