A magnetic detection apparatus can be improved in its product yield. The magnetic detection apparatus includes a resin compact having a the magnet arranged in opposition to an object to be detected for generating a magnetic field, an IC chip with a magnetic detection part built therein for detecting a change in the magnetic field in accordance with movement of the object to be detected, and an IC package in which a lead frame having the IC chip installed thereon is sealed with a resin. A method for manufacturing such a magnetic detection apparatus includes a signal adjustment step for adjusting a signal generated from the magnetic detection part in a state in which the magnetic field is applied to the magnetic detection part to correct a deviation of the signal of the magnetic detection part generated in accordance with a relative displacement between the magnetic detection part and the magnet.