An image-capturing apparatus, in which solid-state image-capturing elements having a large number of pixels are used, capable of suitably performing image-quality correction on a captured image. In a monitor reading mode, a camera system LSI (6) detects the read image signal which is read by thinning out pixels by an image-capturing device (3). Based on the detected data, control values for image-quality correction are computed in a microcomputer (9), and the camera system LSI (6) performs an image-quality correction process on the image signal based on these control values. When the image-capturing device shifts to a capture reading mode, the camera system LSI (6) temporarily stores the image signal, in which all the pixels are read, in the image memory (7), thereafter reads the image signal and detects it. The microcomputer (9) computes a control value on the basis of this detected data and the detected data in the previously used monitor reading mode. Thereafter, the camera system LSI (6) reads the image signal again, and performs an image-quality correction process on the basis of the control values by the microcomputer (9).