An exposure mask and a method of forming a contact hole of a semiconductor device using the same, in which micro patterns can be formed are disclosed herein. In an aspect, an exposure mask method includes a mask substrate, a light-shield pattern formed on the mask substrate, and a transparent pattern in which a plurality of patterns, which are limited to the light-shield pattern and have different short-direction widths and long-direction widths, form a group which is repeatedly arranged. Accordingly, micro photoresist patterns can be formed uniformly.