An electromagnetic thermotherapeutic apparatus includes: a plurality of needle units respectively having head portions and needle portions; a base unit having a base plate that is formed with a plurality of first through holes, and a base pad that is formed with a plurality of second through holes, the needle portions of the needle units removably extending through the second and first through holes, the head portions of the needle units abutting against the base pad; a temperature monitor disposed between the base plate and the base pad; an upper unit disposed above the base pad and abutting against the head portions; and a clamp unit clamping and pressing the base unit against the upper unit.