1. An imaging device comprising: an image capturing unit which generates image data by photoelectrically converting, pixel by pixel, a subject image formed on an available pixel area of a light-receiving surface; a noise obtaining unit reading a noise output from a partial area of said available pixel area; a fixed noise calculating unit which calculates an estimation of fixed pattern noise of said available pixel area by regularly expanding a noise pattern in said available pixel area, the noise pattern being obtained from said noise output read from the partial area; and a noise eliminating unit subtracting said fixed pattern noise from said image data.