Recently, the demand of micro-fabrications such as micro-sensors, microcoils, micro-actuators etc is increasing. Actuators account for a large percentage and volume and weight of a product compared with other parts. Therefore, the progress in downsizing of actuators was required. In order to resolve these problems, the key technology to realizing micro-devices is micro-fabrication process. Particularly, it is essential to the technologies for processing high aspect ratio structures in the production of micro-parts. We have proposed a three-dimensional fabrication process using X-ray lithography technique, and fabricated spiral microcoils having coil lines of narrow pitch and high aspect ratio structures. We have fabricated spiral microcoils at a pitch of 60 μm, and aspect ratio of about 5 using X-ray lithography and narrow metallization techniques on acrylic pipe surface. In addition, we also estimated the suction force of electromagnetic actuators using these microcoils. Measurement results were relatively in good agreement with theoretical values using high aspect ratio microcoils. It is very expected that the high performance microcoils could be manufactured in spite of miniature size.