Abstract: A plurality of semiconductor devices (1) are connected in parallel with each other. A gate driver (13) supplies a gate voltage to gates of the plurality of semiconductor devices (1). A gate wire (14,16) are sequentially connected to the gates of the plurality of semiconductor devices (1) from the gate driver (13). An energizing ability of each of the semiconductor devices (1) indicates how easily collector current flows in response to the supplied gate voltage. The plurality of semiconductor devices (1) having a lower energizing ability are connected closer to the gate driver (13).

Abstract: To ensure continuous incising or coagulating technique without adhesion of carbonized body tissue proteins and fats which may be produced by thermal action of an arc discharge or Joule heat attendant on the electrotomy or electrocoagulation, at least a part of a surgical instrument, such as an electric knife or a forceps, is formed of a C/C composite material.