A magnetic sensor is constituted using magnetic sensor chips mounted on stages supported by interconnecting members and a frame having leads in a lead frame. Herein, the stages are inclined upon plastic deformation of the interconnecting members. When the frame is held in a metal mold and the stages are pressed, the interconnecting members are elastically deformed, so that the magnetic sensor chips are bonded onto the stages placed substantially in the same plane and are then wired with the leads. Thereafter, the stages are released from pressure, so that the interconnecting members are restored from the elastically deformed states thereof. When the magnetic sensor chips are combined together to realize three sensing directions, it is possible to accurately measure three-dimensional bearings of magnetism, and the magnetic sensor can be reduced in dimensions and manufactured with a reduced cost therefore.