Provided is an image forming method of forming an object image by combining a plurality of tomographic images acquired by using an optical coherence tomographic method, including: acquiring, within a first predetermined period, a first three-dimensional image of a first area including a characteristic portion of the object and first tomographic images as a part of the plurality of tomographic images of a second area different from the first area； acquiring, within a second predetermined period, a second three-dimensional image of the first area and second tomographic images as a part of the plurality of tomographic images of the second area, the second tomographic images being different from the first tomographic images； and aligning positions of the first tomographic images and the second tomographic images by using, as references, the characteristic portion included in the first three-dimensional image and the characteristic portion included in the second three-dimensional image.
