Sleep evaluation device and display method for sleep evaluation device

A sleep evaluation device comprising:

• a body motion detection device that detects body motion of a subject;
• and
• an arithmetic operation device that generates display data that displays a level of a sleeping state of the subject, out of a plurality of levels of the sleeping state of the subject, in a predetermined period having a plurality of unit periods on a display device with a graph along a time axis, based on a detection result of the body motion detection device, the arithmetic operation device including:
• a first discrimination device that discriminates the sleeping state of the subject for each unit period, based on the detection result of the body motion detection device;
• a second discrimination device that discriminates the level of the sleeping state of the predetermined period which consists of a predetermined number of continuous unit periods, based on the sleeping state for each unit period discriminated by the first discrimination device providing a continuous number of discrimination results where the sleeping state is found and a ratio of a number of unit periods with the discrimination results where the sleeping state is found to a total number of the unit periods within the predetermined period, and based on a stored determination value for each of the plurality of levels of the sleeping state;
• a decision device that decides a display mode for each predetermined period, according to the level of the sleeping state of the predetermined period;
• and
• a generation device that generates display data that represents the level of the sleeping state of the predetermined period with the display mode.