Recently, one of remarkable tends in the development of optical communication industry is the miniaturization and integration of products. The alignment system of micro optical module is a key apparatus for the miniaturization of optical module and the development of optical communication parts with high functionality. In this research, we have developed a system capable of automatic alignment of a $30mu extrm{m}$-thick film filter and a lensed fiber in order to improve the speed and losses in the optical fiber-to-filter alignment of optical modules. Using the developed automatic alignment system and silicon optical bench, we have measured optical loss and characteristics of the assembled optical add/drop module before packaging $1{ imes}1$ OADM optical module. Whole size of add/drop module was less than $5mm{ imes}5mm{ imes}1mm$. The measured maximum insertion loss was 0.294㏈ that is below 0.3㏈ which is a standard loss of optical module.