To provide a measuring apparatus by which a viscosity coefficient can be measured in a very small region such as a capillary having a very small diameter, by a method wherein the measuring apparatus is composed of a diaphragm and of a probe and the distribution of the viscosity coefficient in the intrusion direction of the probe is found on the basis of the amplitude of a vibration according to the intrusion amount of the probe.

When sine waves are applied to a PZT actuator 4 which is pasted on the side of the supporting point of a diaphragm 1, a bending moment is generated between the actuator 4 and the diaphragm 1, and the diaphragm 1 is vibrated. A probe 2 in a diameter of 200 to 8 μm is attached to the tip of the diaphragm 1 at right angles to the diaphrage 1. The vibration of the diaphragm 1 is converted into a vibration speed signal by a laser Doppler vibration meter 5, and its output is measured by a voltmeter. A capillary 3 is arranged on an X-Y-Z fine-movement stage which can be moved fine to three axial directions. When it is operated, the capillary 3 is raised to the Z-axis direction, and the probe 2 intrudes relatively to a liquid. Since the attenuation of the vibration of the probe 2 is decided only by the viscosity coefficient of the liquid and by the intrusion amount of the probe 2, the distribution of the viscosity coefficient in the intrusion direction is found.