The present invention relates to a module with fixed structures, which comprises a module body, a latch and a resilient snapper mounted on the module body like a cantilever. The latch movably connected to the module body can move between the lock position and the unlock position, and on the module body is set a stop surface for preventing the latch from disengagement. The latch moves between the lock and unlock positions. When in the lock position, the latch is at least partly in the downward movement path of the free end of the resilient snapper; and when in the unlock position, the latch is out of the downward movement path of the free end of the resilient snapper. By employing a latch to control the moving space of the resilient snapper, the structure concerned is simple, and moreover only upon a toggle operation can the latch be switched between different positions. This ensures that only when the latch is unlocked, can the resilient snapper be operated in a way to enable the module to be taken out of the slot. While the latch is locked, incorrect operations are avoidable.