PURPOSE: To make it possible for a human being under a sterilized condition to operate a console without spoiling the sterilized condition, in a medical instrument wherein the sterilization treatment is not possible.

CONSTITUTION: On console 2 on the front face of a coagulation apparatus main body 1, various kinds of push button switches, a knob for rotating operation, a connection terminal, a display panel 6, etc., are provided. Fixing nuts are provided on both ends of the console 2. A panel 90 which can be sterilized is fixed removably on the front end part of the coagulation apparatus main body 1. The panel 9 is constituted by providing a fixing member 11 fixed on the fixing nuts, a push button member 12 under a condition connected with the push button switches and a rotating knob 13 connected with a rotation operating knob so as to be operable from the surface side. In addition, on a panel sheet part 10, a joint member 14 connected with the connection terminal and constituting the same terminal as it on the surface is provided.