To provide a magnetic sensor and a magnetic sensor device capable of suppressing noise and having high sensitivity.SOLUTION: A magnetic sensor according to the present embodiment comprises: a magnetic field detection part having a magnetic layer the length of which in a first direction is 10 times the length in a second direction orthogonal to the first direction or more, and the length of which in a third direction orthogonal to the first direction and the second direction is 1/2 the length in the second direction or less； a first magnetic substance member arranged along the first direction of the magnetic field detection part and the length of which in the third direction is longer than the length of the magnetic layer in the third direction； a first nonmagnetic insulation layer arranged between the magnetic field detection part and the first magnetic substance member and the length of which in the second direction is 1/2 the length of the magnetic layer in the second direction or less； and a circuit for sending a current to the magnetic layer.SELECTED DRAWING: Figure 1【課題】ノイズを抑制することができるとともに高い感度を有する磁気センサおよび磁気センサ装置を提供する。【解決手段】本実施形態の磁気センサは、第１方向の長さが前記第１方向に直交する第２方向の長さの１０倍以上でかつ前記第１方向および前記第２方向に直交する第３方向の長さが前記第２方向の長さの１／２以下である磁性層を有する磁界検出部と、前記磁界検出部の前記第１方向に沿って配置され、前記磁性層の前記第３方向の長さより前記第３方向の長さが長い第１磁性体部材と、前記磁界検出部と前記第１磁性体部材との間に配置され、前記第２方向の長さが前記磁性層の前記第２方向の長さの１／２以下である第１非磁性絶縁層と、前記磁性層に電流を流す回路と、を備えている。【選択図】図１
