1. A floating image interaction device, comprising: an imaging optical system including a refracting surface whereas paths of light rays are bent at a plane; and a user object detecting means, whereby for an object to be projected placed to one side of said refracting surface, said imaging optical system forms a real image of said object on the opposite side of said refracting surface with front and back being reversed, and said user object detecting means capable of detecting the position, or the position and shape of user objects approaching said real image.