A magnetic detection device comprising a substrate having recesses (11A, 11B, 21A, 21B, 31A, 31B) and magnetoresistive elements provided on inclined side surfaces (13, 14, 23, 24, 33, 34) of the recesses (11A, 11B, 21A, 21B, 31A, 31B), wherein Z detection recesses (11A, 11B) are disposed at least at two locations, each Z detection recess (11A, 11B) including a first inclined side surface and a second inclined side surface opposing each other with a distance therebetween gradually increasing toward a substrate surface, the first inclined side surface and the second inclined side surface having the magnetoresistive elements (40, R1, R2, R3, R4) provided thereon, wherein the magnetoresistive elements (40, R1, R2, R3, R4) each include a fixed magnetic layer, a free magnetic layer, and a nonmagnetic intermediate layer formed between the fixed magnetic layer and the free magnetic layer, and a direction of fixed magnetization of the fixed magnetic layer of each magnetoresistive element (40, R1, R2, R3, R4) is oriented along a corresponding one of the inclined side surfaces (13, 14) obliquely to a thickness direction of the substrate, wherein a bridge circuit is formed by connecting two element lines in parallel, each element line being formed by connecting in series two of the magnetoresistive elements (40, R1, R2, R3, R4) having the directions of fixed magnetization oriented toward opposite sides in the thickness direction of the substrate, wherein the bridge circuit detects a magnetic field in a Z direction, the Z direction being the thickness direction of the substrate, and wherein, in each of the Z detection recesses (11A, 11B), the direction of fixed magnetization of the magnetoresistive element (R1, R4) provided on the first inclined side surface and the direction of fixed magnetization of the magnetoresistive element (R2, R3) provided on the second inclined side surface are oriented toward the opposite sides in the thickness direction of the substrate. characterised in that the two magnetoresistive elements (R1, R2, R3, R4) being serially connected in the bridge circuit and having the directions of fixed magnetization oriented toward opposite sides in the Z direction are located on the inclined side surfaces (13, 14) of the same Z detection recess (11A, 11B). wherein Z detection recesses (11A, 11B) are disposed at least at two locations, each Z detection recess (11A, 11B) including a first inclined side surface and a second inclined side surface opposing each other with a distance therebetween gradually increasing toward a substrate surface, the first inclined side surface and the second inclined side surface having the magnetoresistive elements (40, R1, R2, R3, R4) provided thereon, wherein the magnetoresistive elements (40, R1, R2, R3, R4) each include a fixed magnetic layer, a free magnetic layer, and a nonmagnetic intermediate layer formed between the fixed magnetic layer and the free magnetic layer, and a direction of fixed magnetization of the fixed magnetic layer of each magnetoresistive element (40, R1, R2, R3, R4) is oriented along a corresponding one of the inclined side surfaces (13, 14) obliquely to a thickness direction of the substrate, wherein a bridge circuit is formed by connecting two element lines in parallel, each element line being formed by connecting in series two of the magnetoresistive elements (40, R1, R2, R3, R4) having the directions of fixed magnetization oriented toward opposite sides in the thickness direction of the substrate, wherein the bridge circuit detects a magnetic field in a Z direction, the Z direction being the thickness direction of the substrate, and wherein, in each of the Z detection recesses (11A, 11B), the direction of fixed magnetization of the magnetoresistive element (R1, R4) provided on the first inclined side surface and the direction of fixed magnetization of the magnetoresistive element (R2, R3) provided on the second inclined side surface are oriented toward the opposite sides in the thickness direction of the substrate. characterised in that the two magnetoresistive elements (R1, R2, R3, R4) being serially connected in the bridge circuit and having the directions of fixed magnetization oriented toward opposite sides in the Z direction are located on the inclined side surfaces (13, 14) of the same Z detection recess (11A, 11B).