A mirror-less digital image processing apparatus comprising: an imaging lens comprising a focusing lens; a lens driving unit that drives the focusing lens; an imaging device comprising imaging pixels for capturing a light transmitted through the focusing lens and generating image signals, and phase difference detecting pixels for detecting phase difference of a captured image; said imaging device outputting only image signals of a designated number of pixels sampled by the imaging device as a live-view image, when the live-view image is displayed, and outputting all pixels, when a still image is captured; and a control unit that controls the phase difference detecting pixels to perform focus detection by detecting phase difference of a live-view image while the live-view image is output from the imaging pixels, wherein, in a continuous photographing mode for continuously capturing still images, the control unit comprises: a first calculation unit that performs a first focus detection by detecting phase difference of a still image captured during a first image capture operation; a second calculation unit that performs a second focus detection by detecting phase difference of a still image captured during a second image capture operation; a moving speed determining unit that determines moving speed of an object based on results of the first focus detection and the second focus detection; and a focus location correcting unit that corrects focus location by driving the focusing lens based on the determined moving speed of the object; wherein the continuous photographing mode comprises: a first continuous photographing mode, in which the imaging device outputs a live-view image; and a second continuous photographing mode, in which the imaging device does not output a live-view image; and wherein the number of still images captured during a unit time period in the second continuous photographing mode is greater than the number of still images captured during the unit time period in the first continuous photographing mode. an imaging lens comprising a focusing lens; a lens driving unit that drives the focusing lens; an imaging device comprising imaging pixels for capturing a light transmitted through the focusing lens and generating image signals, and phase difference detecting pixels for detecting phase difference of a captured image; said imaging device outputting only image signals of a designated number of pixels sampled by the imaging device as a live-view image, when the live-view image is displayed, and outputting all pixels, when a still image is captured; and a control unit that controls the phase difference detecting pixels to perform focus detection by detecting phase difference of a live-view image while the live-view image is output from the imaging pixels, wherein, in a continuous photographing mode for continuously capturing still images, the control unit comprises: a first calculation unit that performs a first focus detection by detecting phase difference of a still image captured during a first image capture operation; a second calculation unit that performs a second focus detection by detecting phase difference of a still image captured during a second image capture operation; a moving speed determining unit that determines moving speed of an object based on results of the first focus detection and the second focus detection; and a focus location correcting unit that corrects focus location by driving the focusing lens based on the determined moving speed of the object; wherein the continuous photographing mode comprises: a first continuous photographing mode, in which the imaging device outputs a live-view image; and a second continuous photographing mode, in which the imaging device does not output a live-view image; and wherein the number of still images captured during a unit time period in the second continuous photographing mode is greater than the number of still images captured during the unit time period in the first continuous photographing mode. a first calculation unit that performs a first focus detection by detecting phase difference of a still image captured during a first image capture operation; a second calculation unit that performs a second focus detection by detecting phase difference of a still image captured during a second image capture operation; a moving speed determining unit that determines moving speed of an object based on results of the first focus detection and the second focus detection; and a focus location correcting unit that corrects focus location by driving the focusing lens based on the determined moving speed of the object; wherein the continuous photographing mode comprises: a first continuous photographing mode, in which the imaging device outputs a live-view image; and a second continuous photographing mode, in which the imaging device does not output a live-view image; and wherein the number of still images captured during a unit time period in the second continuous photographing mode is greater than the number of still images captured during the unit time period in the first continuous photographing mode.