A stop position adjusting device for an accessor mechanism in an information recording device using a recording cartridge, includes: the accessor mechanism; a first moving mechanism; a second moving mechanism; and an image taking section. The accessor mechanism inserts the recording cartridge into a cell and takes out the recording cartridge from the cell. The first moving mechanism moves the accessor mechanism in a first direction. The second moving mechanism moves the accessor mechanism in a second direction different from the first direction. The image taking section is provided on the accessor mechanism and detects a position of a mark provided near the cell. An adjustment of a stop position of the accessor mechanism for the cell is executed based on the position detected by the image taking section.