A reduced size/thickness magnetic detection device includes: a substrate; and a magneto-impedance element at one substrate surface side and including a magneto-sensitive wire and a detection coil. The wire senses an external magnetic field component in a first axis direction in which the wire extends. The coil loops around the wire, and includes left-side and right-side coil parts coexisting along the wire, and a magnetic field direction changing body of soft magnetic material having at least a part at another substrate surface side or in the substrate above an intermediate position between left-side and right-side coil parts. The body can change an external magnetic field component in a third axis direction intersecting the substrate to a measurement magnetic field component in the first axis direction. The external magnetic field component in the third axis direction can be detected from a left-side coil part output and a right-side coil part output.