Target material conversion method, crystal manufacturing method, composition manufacturing method, and target material conversion device

Provided are a target material conversion device, a composition manufacturing method, a crystal manufacturing method and a target material conversion method capable of easily and effectively increasing the concentration of a target material. This method, which converts a target material (103) in a first phase (101), formed from a solid phase or a liquid phase containing the target material (103), to a second phase (102), is characterised by comprising: an approximation step for bringing the first phase (101) and the second phase (102) close together; and a bubble disintegration step for generating bubbles in the vicinity of the boundary between the first phase (101) and the second phase (102) and causing the bubbles to disintegrate.