This study aims to create an interface for visualizing numerical data on a head-mounted display (HMD) and introduce functions to allow control of this visualization via hand gestures. HMDs have the advantage of providing a user with a 360-degree field of view without taking up a lot of space. However, it is difficult to control visualized numerical data intuitively with this type of display because the user cannot see his/her own hand. We therefore introduced functions allowing the user to control the virtual scene with visualized virtual hands. We developed a system in which a virtual menu is presented to the users and they can change the visualization method by pushing virtual panels. The user can move freely in the visualized virtual scene. Moreover, to help users share their thoughts, we have introduced a drawing function that enables users to indicate points and areas of interest in the visualized scene. (C) 2016 The Japan Society of Plasma Science and Nuclear Fusion Research