IMAGE ACQUISITION METHOD, IMAGE ACQUISITION DEVICE, PROGRAM AND CULTURE CONTAINER

[Object] To provide an image acquisition apparatus, an image acquisition method, a program, and a culture vessel which are suitable for imaging a change in size due to a change of a cell over time at a suitable focus position and acquiring an image. [Solving Means] An image acquisition method includes: acquiring, by an imaging unit, an image of a cell in a culture vessel including a recess containing the cell; calculating an outer diameter of the cell on a basis of the image acquired by the imaging unit; and determines a focus position of the imaging unit on a basis of the calculation result of the outer diameter by referring to a table in which the plurality of focus positions of the imaging unit, which are different from each other, and outer diameters of the cell are associated with each other, the table being generated in advance.