An information recording device and a method of recording the information, in which the state around a user may be recorded efficiently includes a change sensor that maps three sorts of bio-information, as measured by a bio-information sensor, namely the number of heart beats, GSR (galvanic skin response), and the skin temperature difference, in a three-dimensional feature space, as observed values, and generates classes on the three-dimensional feature space. The change sensor compares a class to which a newly measured observed value belongs to a class to which belong the values measured in the past in order to detect a change in the user when the classes differ from each other. On detection of the changes by the change sensor, a controller actuates a video camera, a still camera, and a microphone to record the image and the sound around the user.