To provide a method and a device for assembling an optical disk cartridge by which an optical disk such as a DVD can be efficiently and properly assembled.

A shell half 201a of one side is mounted on a turn table 1. A slider unit which sliding-guides and also elastically energizes a slide shutter 202 is loaded on the shell half 201a. The optical disk 203 is loaded on the shell half 201a. The shell half 201a and the shell half 201b are laminated and are mutually bound. A slide shutter 202 is loaded on a case 201 composed of joined shell halves so as be able to slide. When loaded on the shell half 201a, a slider 204 is engaged to a hook part 205a of a coil spring 205 in advance.