In this study, we fabricate a the blood pressure measurement device based on the arterial tonometry method with a convex micro pressure sensor array for reducing a cross talk of the sensor. The size of our device is 30 × 30 × 5.8 mm3. It has 11 pressure sensors that are 130 × 250 × 20 µm3 in size. Because each pressure sensor element has a convex surface shape, the pressure measured by each sensor element has little effect on the others. Thus, a clear blood pressure pulse wave can be measured by reducing the cross talk of the sensor.