Recently, graphene has attracted attention as a new material for the electronic applications. Graphene is a monolayer of carbon, and it has outstanding properties, high carrier mobility, ultrathin body, and linear band structure. Therefore various electronic applications have been studied vigorously such as high-speed transistors, photo detectors, flexible electronics, chemical and physical sensors. In automotive applications, magnetic field sensors is widely used for detecting position and current, nowadays the production is around 10 billion units per year. However, magnetic field sensors are required to be highly precise with good usability. To satisfy the demand, we have developed graphene Hall elements that sense magnetic field by Hall effect. The sensitivity of Hall elements is proportional to the carrier mobility, and graphene has extremely high carrier mobility as compared with the conventional materials like Si, GaAs and InSb, so graphene Hall elements are expected to be high sensitivity that enables to sense Earth’s magnetic field about 50 μT. In addition, graphene has low temperature dependence of carrier mobility due to ballistic transport, so good usability to actual use environment is also expected. In this paper, we demonstrate graphene Hall elements made by conventional Si process technology. Our devices show that the sensitivity is 0.1 V/VT with the mobility about 2,000 cm2/Vs, and thermal coefficient of sensitivity (TCS) is 2800 ppm/degree Celsius. These data indicates possibility of graphene Hall elements for actual use. Additionally, we also show practical data such as contact resistance, offset voltage, linearity, and those of temperature dependence with the difference of the operation modes, constant-voltage and constant-current. In particular, we consider that offset voltage is one of the important subjects. Furthermore, we discuss the points to develop graphene Hall elements. Finally, we will mention the prospects of the devices of graphene for other automotive applications.