Powder material for three-dimensional object formation, hardening liquid and three-dimensional object formation kit, and formation method and formation apparatus of three-dimensional object

A three-dimensional object formation apparatus, comprising:

• a powder material layer forming unit configured to form a layer of a powder material for three-dimensional object formation that comprises a base material coated with an organic material;
• a hardening liquid delivering unit configured to deliver a hardening liquid that comprises a cross-linking agent cross-linkable with the organic material in order to harden a predetermined region of the layer of the powder material for three-dimensional object formation formed by the powder material layer forming unit;
• a powder material containing unit containing the powder material for three-dimensional object formation;
• and
• a hardening liquid containing unit containing the hardening liquid.