We present the 9 and 18 \micron luminosity functions ( LFs ) of galaxies at 0.006 \leq z \leq 0.8 ( with an average redshift of \sim 0.04 ) using the AKARI mid-infrared all-sky survey catalog .
We selected 243 galaxies at 9 \micron and 255 galaxies at 18 \micron from the Sloan Digital Sky Survey ( SDSS ) spectroscopy region .
These galaxies were then classified by their optical emission lines , such as the line width of H \alpha or by their emission line ratios of [ OIII ] /H \beta and [ NII ] /H \alpha into five types : Type 1 active galactic nuclei ( AGN ) ( Type 1 ) ; Type 2 AGN ( Type 2 ) ; low-ionization narrow emission line galaxies ( LINER ) ; galaxies with both star formation and narrow-line AGN activity ( composite galaxies ) ; and star-forming galaxies ( SF ) .
We found that ( i ) the number density ratio of Type 2 to Type 1 AGNs is 1.73 \pm 0.36 , which is larger than a result obtained from the optical LF and ( ii ) this ratio decreases with increasing 18 \micron luminosity .