Characterization of pitch and roll motions of the slider in the hard disk gimbal system is important to achieve higher aerial recording densities. This paper describes a novel piezoresistive-type microsensor that could be directly mounted on the existing slider/gimbal system of a hard disk drive to simultaneously measure the pitch and roll angles of the slider. The size of the fabricated microsensor is designed as 1 mm×1 mm×0.1 mm for picoslider applications and the sensor is fabricated by a silicon micromachining process for mass production. The dynamic behavior of the system is slightly altered as expected in a simulation after the sensor is mounted on the slider and the fundamental frequency shift of pitch and roll motion is calculated to be less than 5% of the original system but it is believed that this sensor could provide the best in situ measurement than other currently existing methods. Experimentally, the prototype sensor is capable of detecting pitch and roll angles within ± 3° and the performance is compared with interferometric measurement data and the mismatch is nominally within 14% in average.