A magnetic sensor is provided, including: a substrate; a plurality of magneto resistance element portions, disposed above the substrate, each including: a free magnetic layer having a magnetization direction changeable by an external magnetic field; and a pin magnetic layer having a fixed magnetization direction; and a plurality of heater portions corresponding to the magneto resistance element portions, respectively, and configured to heat a corresponding pin magnetic layer, wherein the magnetization direction of the pin magnetic layer of one magneto resistance element portion is different from the magnetization direction of the pin magnetic layer of another magneto resistance element portion on a plane parallel to a surface of the substrate, when the external magnetic field is applied to each of the magneto resistance element portions, the magnetic sensor detects a physical amount based on a change in a resistance of each of the magneto resistance element portions.