In an imaging device of the present invention, an imaging element 2 is driven in a thinning read-out mode for reading out signal charges from a subset of pixels, or in an all-pixels read-out mode for reading out signal charges from all pixels. When the imaging element 2 is driven in the thinning read-out mode, the imaging device processes and records a series of first image data that is obtained by reading out signal charges from the subset of pixels and that constitutes the moving images. When the imaging element 2 is driven in the all-pixels read-out mode, the imaging device processes and records a series of second image data constituting moving images after the number of pixels of the second image data is thinned, and processes and records a portion of the second image data as a still image without thinning when an instruction to pick up the still image is given while picking up the moving images.