A magnetic resolver that includes: an annular stator portion having a protruding core; an annular coil substrate on which a coil portion, which is disposed around the protruding core, is formed as a patterned thin-film coil; and a rotor portion disposed to face the stator portion from above, with the coil substrate interposed therebetween, wherein the amount of overlap between a top face of the protruding core and the rotor portion, when viewed from above, varies as a rotation angle of the rotor portion relative to the stator portion varies. The annular coil substrate may be constituted of substrate pieces that have shapes obtained by dividing the annular shape, which facilitates increasing the yield rate in the number of substrate pieces that can be produced from a substrate material.