Abstract: A cone-plate type apparatus for evaluating compatibility with blood or the like includes: a bottom plate (1) that secures test material (2), a cone (16) made of transparent material that rotates while in contact with blood or the like supplied upon the test material, a cone holder (13) that secures the cone therein and that has a rotary driver (14) on its periphery, a driving apparatus (8) that rotates the cone holder via the rotary driver and an incident light fluorescent microscope (2) for observing blood or the like on the test material from above the cone. The test material is secured to the bottom plate by means of ring members so it is possible to observe and quantitatively evaluate the state of adherence of blood cell components to not only plate-shaped material but also materials having the shape of a membrane, sponge, filter or any other shape, along with opaque materials, in the presence of shear stresses and in real time.