A magnetic sensor for detecting magnetism generated from a conductor in which a current flows in a first direction includes a magnetic detection unit capable of detecting the magnetism, a magnetization core, and a magnetic shield. The magnetization core includes a first core section, which is substantially parallel to the first direction, and a second core section and third core section, which are each continuous from both end portions of the first core section in a second direction that is orthogonal to the first direction. The second core section and the third core section each extend from an end portion of the first core section to follow a third direction that is orthogonal to the first direction and the second direction. The magnetic detection unit has a sensitivity direction in the second direction and is positioned in a core gap sandwiched between the vicinity of the end portion of the second core section and the vicinity of the end portion of the third core section in the third direction. The magnetic shield includes a plate-shaped shield portion positioned to overlap the core gap when viewed along the third direction.