To culture a bigfin reef squid or develop a new fishing ground for the bigfin reef squid by providing an artificial spawning bed for the bigfin reef squid.

This artificial spawning bed for the bigfin reef squid is characterized by fixing the lower end (1a) of a cage body (1) composed of carbon fiber strings to the bottom (3) of the sea and mounting a float (5) onto the top (1b) of the cage body (1). Furthermore, the cage body (1) is obtained by arranging an inner cage (13) composed of the carbon fiber strings in the interior of an outer cage (11) composed of the carbon fiber strings.