An image capturing apparatus includes an image capturing section and capture control section. The image capturing section converts the shape of an object into an electrical quantity in accordance with the parameter value set in a parameter setting section, and outputs image data representing an image corresponding to the shape of the object. The capture control section receives the image data output from the image capturing section, calculates an evaluation index for evaluating the image quality of the image from the image data. If the evaluation index falls outside the range of a preset reference value, the capture control section changes the parameter value set in the parameter setting section so as to make the evaluation index fall within the range of the reference value to output the image data which is received from the image capturing section and the evaluation index of which falls within the range of the reference value. An image capturing method and a fingerprint collation method and apparatus are also disclosed.