A smear preparing apparatus that operates under selectable operation modes, may include: a smearing unit that prepares smeared slides by smearing samples onto slides; a staining unit that is capable of housing the smeared slides and that performs staining processing by accommodating a staining solution used to stain the samples on the housed smeared slides; a fluid circuit that supplies the staining solution to the staining unit; and a controller that controls the supplying of the staining solution to the staining unit depending on a selected one of the operation modes.