Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a standard procedure for precise histological diagnosis of pancreas tumors, but it is sometimes difficult to obtain adequate specimens. EUS Sonopsy CY® is a newly designed needle with original features. This randomized study will compare the tissue collection rate of EUS Sonopsy CY® to that of a conventional needle in EUS-FNA. The major eligibility criteria are as follows: Patients with a pancreatic mass referred for EUSFNA; age 20 years, and performance status＜4. The primary outcome is the tissue collection rate. This study will elucidate the efficacy of EUS Sonopsy CY®.