Methods for providing new transparent near infrared absorptive fine particles having a wide range of near infrared absorption, which are an assembly of hexaboride fine particles, where when a particle shape of the number of particles contained in the assembly is approximately regarded as a spheroid body, there are 20% or more and less than 80% of particles having an aspect ratio [(long axis length)/(short axis length)] of 1.5 or more and less than 5.0, and there are 20% or more and less than 80% of particles having an aspect ratio of 5.0 or more and less than 20.0.