PURPOSE: To provide an automatic equal time dyeing apparatus for a slide sample, said apparatus has high dyeing work efficiency and lessenes the burden of an operator.

CONSTITUTION: After a large number of slide holder baskets (baskets in a short form) are set in a supplying tank 4, an apparatus is driven. The supplying tank 4 moves and transports simultaneously a large number of the baskets rightward by one step to put a basket at the right end in a moving tank 6 and raise it. Then, a holding and sending apparatus 10 starts driving, holds the basket in the moving tank 6, transports it leftward by one step, and immerses it in a medical liquid tank 7 at the right end. The baskets are immersed successively from the one at the right end in the medical liquid tank 7 for equal period to dye the baskets by repeating those processes. The baskets for which dyeing is finished are put in a transporting tank 20, an elevator 21 is lowered to recover the baskets in a taking out tank 24, and the baskets are moved to a sealing process as they are.