In this study, we reports on a wearable blood pressure measurement device based on the arterial tonometry method. The device consists of a force sensor, a band, and a 3D printed jig for fixing the sensor to the band. The force sensor was embedded in polydimetyilsiloxane (PDMS) with a guide shape. Since misalignment of the measurement position by body motion was prevented by the guide, the decrement of amplitude of blood pressure was suppressed. Furthermore, we fabricated a micro force sensor with piezo-resistive beams for increasing the sensitivity. Since the sensitivity of the senor is high, the amplitude of measured blood pressure was increased to 345 mV. It shows that the blood pressure can be measured clearly by the wearable device with micro force sensors with PDMS guide.