The cell observation device and method aims to easily study the correlation between initial states of cells and their reactions without using a synchronous culture method. For this purpose, the cell observation device includes an image acquisition unit acquiring an image of a specimen including a plurality of cells; a stimulating unit applying a predetermined stimulation to the plural cells; a determining unit determining initial states of the plural cells from the image which is acquired by the image acquisition unit before the stimulating unit applies the stimulation; a finding unit finding reactions of the plural cells to the stimulation, from the image acquired by the image acquisition unit after the stimulating unit applies the stimulation; and a generating unit generating information on correlation between the initial states and the reactions of the plural cells.