A pathological specimen preparation device includes a stage portion including a stage, a reagent supply portion 150 capable of supplying a reagent to a substrate W mounted on the stage, a washing portion capable of supplying a washing solution to the substrate, an electric field stirring portion capable of stirring the reagent or the washing solution supplied to the substrate by applying an electric field to the reagent or the washing solution, and a control unit, wherein the washing portion, the reagent supply portion, and the electric field stirring portion are sequentially disposed in a Y direction as a first direction, and the device includes a stage transport mechanism that moves the stage in the Y direction, and a stage tilting mechanism that tilts the stage in an X direction as a second direction crossing the Y direction when the stage is positioned in the washing portion.