A magnetic sensor 1 includes: a non-magnetic substrate 10; and a sensitive element 30 disposed on the substrate 10. The sensitive element 30 has a longitudinal direction and a transverse direction and has a uniaxial magnetic anisotropy in a direction intersecting the longitudinal direction. The sensitive element 30 is configured to sense a magnetic field by a magnetic impedance effect. The sensitive element 30 includes a soft magnetic material layer 101 made of an amorphous alloy based on Co and having a saturation magnetization of greater than or equal to 300 emu/cc and less than or equal to 650 emu/cc.