A head mounted device suitable for guiding an exhibition is disclosed. The head mounted device includes an image capturing unit, a process module and an information interface. The process module includes a recognition unit, a computing unit and a control unit. The image capturing unit captures an input image in invisible spectrum. The recognition unit recognizes an invisible code from the input image. The computing unit calculates a relative distance and a relative angle between the head mounted device and an exhibition object. By comparing the relative distance with a threshold distance, the control unit determines whether to trigger the information interface and present an exhibit-object introduction based on relative distance and relative angle.