A capture method and a capture device are capable of increasing the amount of screen data that can be saved as log. The information of screen data displayed on a screen is acquired, and the active screen data is captured when determined that the active screen data is from application software to be captured based on the information of the screen data. In the capture processing step, an image data of a current active screen is presumptively configured so as to include a last active screen retrieved immediately before said current active screen that is positioned in a screen region other than said current active screen. A pixel difference between a pixel date of a current full-screen region and a pixel date of a last full-screen region is taken, and the pixel difference data as said active screen data is retrieved.