PROBLEM TO BE SOLVED: To provide a biological examination apparatus which minimizes attenuation of light intensity and elastic wave due to a biological tissue, can irradiate an object with light energy below MPE with high efficiency, and can detect the elastic wave in a high S/N ratio.SOLUTION: A biological examination apparatus comprises: a light source for generating light to irradiate an object elastic wave detection means for detecting elastic wave generated by the object which has absorbed the irradiated light and an acoustic matching layer whose one surface comes into contact with the elastic wave detecting means and the other surface comes into contact with the object. The apparatus is configured to allow the light to pass through the acoustic matching layer and then irradiate the object. The apparatus also comprises light diffusing means for irradiating the object with light having substantially uniform intensity regardless of a position inside the acoustic matching layer.SELECTED DRAWING: Figure 1
