To provide a high-quality needle-like micro-particle structure utilizable in a micro-form as a colorant and to provide a method for producing the structure.

The needle-like micro-particle structure is obtained as follows. A micro-particle dispersion 202 in which spherical monodisperse silica particles are dispersed in a dispersion medium is introduced into a container 203 and one end of a capillary 201 is dipped in the micro-particle dispersion 202. Furthermore, the micro-particle dispersion 202 enters even the interior of the capillary 201 by capillarity. Since the dispersion medium is evaporated at the top of the capillary 201, alignment of the micro-particles starts at the top in the interior of the capillary 201. Since the dispersion medium is evaporated at the top of the capillary 201, the micro-particles are fed into the capillary 201. Thereby, the needle-like micro-particle structure 205 accumulates in the capillary 201. The dispersion medium in the capillary 201 is then sufficiently evaporated and removed. When the capillary is removed, the resultant structure can be utilized even as a colorant or other optical materials.