Production method for group 13 nitride single crystal and production apparatus for group 13 nitride single crystal

This production method for a group 13 nitride single crystal (40) includes a dissolving step and a crystal growth step. The dissolving step is a step for dissolving nitrogen into a mixture melt (24) in a reaction vessel (52), which holds the mixture melt (24), a seed crystal (30), and a surrounding member (90) in the inside thereof. The mixture melt (24) contains an alkali metal and a group 13 metal. The seed crystal (30) is a seed crystal that is placed in the mixture melt (24), is composed of a group 13 nitride crystal, and has a c-plane as the principal plane. The surrounding member (90) is arranged so as to surround the entire area of the side surface of the seed crystal (30). The crystal growth step allows crystal growth of a group 13 nitride crystal (32) on the seed crystal (30).