Living body observation method and living body observation device

A living body observation method for observing a surface of an observation target excised from a living body, the method comprising:

• applying a fluorescent substance that emits fluorescence by binding to a cancer cell and has an excitation wavelength in a range of 300 nm to 650 nm to the observation target;
• irradiating the observation target with excitation light including the excitation wavelength using a light source;
• cutting the excitation light from observation light emitted from the observation target using a filter;
• capturing the observation light from which the excitation light is cut and outputting image data using a camera;
• storing a reference image which is an image of the observation light after the fluorescent substance is applied on the basis of the image data;
• acquiring a target image which is an image of the observation light after acquisition of the reference image on the basis of the image data and generating an analysis image indicating change in light intensity of the target image with respect to the reference image using an image processing device;
• and
• outputting the analysis image using an output device.