A wireless power supply apparatus for wirelessly supplying power to a capsule-type medical device that is introduced into a body of a subject and receives an electric power by means of a changing magnetic field, comprising: detecting means for detecting a position and orientation of the capsule-type medical device; a power transmission coil unit that is arranged on the subject, and that has three sets of power transmission coils (44, 45, 46) that generate a magnetic field in three orthogonal directions that are orthogonal to each other, each set of power transmission coils (44, 45, 46) having two coils (44A-46B); drive means for applying an alternating electric current to at least one set of the power transmission coils (44, 45, 46), and first coil selection means (51, 70a-70f) for selecting at least one set of the sets power transmission coils (44, 45, 46) to apply the electric current to the at least one selected set of power transmission coils selected by the first coil selection means (51, 70a-70f) in order to generate the changing magnetic field; characterized by second coil selection means (51, 70g-70m) adapted to select two sets of power transmission coils (44, 45, 46) from the three sets of power transmission coils (44, 45, 46), to serially connect the selected two sets of power transmission coils (44, 45, 46) selected by the second coil selection means (51, 70g-70m), and to serially apply a current to the serially connected two sets of power transmission coils (44, 45, 46) selected by the second coil selection means (51, 70g-70m), when the orientation of the capsule-type medical device detected by the detecting means corresponds to the middle between two orthogonal directions. detecting means for detecting a position and orientation of the capsule-type medical device; a power transmission coil unit that is arranged on the subject, and that has three sets of power transmission coils (44, 45, 46) that generate a magnetic field in three orthogonal directions that are orthogonal to each other, each set of power transmission coils (44, 45, 46) having two coils (44A-46B); drive means for applying an alternating electric current to at least one set of the power transmission coils (44, 45, 46), and first coil selection means (51, 70a-70f) for selecting at least one set of the sets power transmission coils (44, 45, 46) to apply the electric current to the at least one selected set of power transmission coils selected by the first coil selection means (51, 70a-70f) in order to generate the changing magnetic field; characterized by second coil selection means (51, 70g-70m) adapted to select two sets of power transmission coils (44, 45, 46) from the three sets of power transmission coils (44, 45, 46), to serially connect the selected two sets of power transmission coils (44, 45, 46) selected by the second coil selection means (51, 70g-70m), and to serially apply a current to the serially connected two sets of power transmission coils (44, 45, 46) selected by the second coil selection means (51, 70g-70m), when the orientation of the capsule-type medical device detected by the detecting means corresponds to the middle between two orthogonal directions.