The invention discloses a surgical device for introducing substances into biological tissues by using needles. The surgical device comprises a microwave power source; a needle being capable of inserting into the biological tissues, the needle having an elongated body ending at an insertion tip; a longitudinal channel formed in the body and used for transmitting the substances into or out of the tissues; and a coaxial antenna comprising an inner conductor along an inner wall of the channel and an outer conductor being coaxial with the inner conductor and separated with the inner conductor through dielectric materials. The needle is selectively connected to the microwave power source via a measurement path for transmitting the microwave energy by a measuring power level or an ablation path for transmitting the energy by an ablation power level so as to receive energy from the microwave power source. The coaxial antenna is connected so as to couple the received energy to the biological tissues at the needle tip. The energy transmitted on the measurement path has a first frequency, and the energy transmitted on the ablation path has a second frequency larger than the first frequency.