An image recording apparatus includes: a tray for holding a medium; a conveying portion for conveying the tray; a recording portion for recording an image onto the medium held by the tray; a detecting portion for detecting the medium. A detection-region determining portion determines, a detection region of the medium which is to be detected and a detection-region memory portion memorizes the determined detection region. Prior to the next image recording, the detecting portion detects the detection region, based on the detection region that has been memorized in previous image recording. A judging portion judges whether the image has been already recorded onto the medium or not, based on result of detection made by the detecting portion.