The Korea Basic Science (KBSI) is developing a Gas Cluster Ion Source (GCIS) for X-ray Photoelectron Spectroscopy (XPS) and Secondary Ion Mass Spectroscopy (SIMS) since 2014. The experimental system was installed for generation of argon gas cluster ion beam using GCIS which consists of cluster generator, ionizer, Wien filter, accelerator, micro lens and target. For analysis of gas cluster ion beam, we had manufactured a Wien filter with wide range. From experimental results of Wien filter with wide range, a compact Wien filter for GCIS beam line was developed. In this paper, feasibility design studies of Wien filter related to analysis of cluster ion beam are exposed.