Disclosed herein is an image displaying method for a head-mounted type display unit which includes a frame of the glasses type for being mounted on the head of an observer, an image display apparatus attached to the frame, and a control section for controlling image display of the image display apparatus. The image display apparatus includes an image forming apparatus, and an optical apparatus. The image displaying method includes the steps of: storing a data group configured from a plurality of data in a storage section; adding a data identification code to each of the data; sending a designation identification code and display time information at predetermined intervals of time; and reading out the data whose data identification code coincides with the received designation identification code from the storage section and controlling the image forming apparatus to display an image based on the read out data.