System in which a phase transition type recording film (2) is used as an information recording medium, and for recording information, a focused electron beam is selectively projected on desired positions of the recording film so as to locally heat the recording film and cause phase transition, while for retrieving information, an electron beam having energy at a degree not causing the phase transition is projected so as to utilize the fact that reflection or diffraction (7) of the primary electron beam (6) projected at the retrieval differs between the recorded regions (22a, 22b) and unrecorded regions (21a, 21b, 21c).