A medical apparatus comprising: a first connector portion including an insertion hole portion and a ring-shaped terminal juxtaposition portion on which a plurality of terminals are juxtaposed along an inner peripheral surface of the insertion hole portion; a second connector portion including a cylindrical insertion-side connector body having an outer peripheral surface and a ring-shaped terminal juxtaposition portion on which a plurality of electrical contact portions are juxtaposed in a circumferential direction on said outer peripheral surface of the cylindrical insertion-side connector body, wherein said plurality of electrical contact portions of said second connector portion are configured to be connected to the plurality of terminals of the first connector portion when said cylindrical insertion-side connector body of said second connector portion is inserted into said insertion hole portion of said first connector portion; a removing member provided in the first connector portion and including a sliding contact portion which is configured to remove moisture on the plurality of electrical contact portions by coming into sliding contact with the outer peripheral surface of said cylindrical insertion-side connector body when the plurality of terminals of said first connector portion are connected to the plurality of electrical contact portions of said second connector portion, a distal end portion of the outer peripheral surface of said cylindrical insertion-side connector body being configured to first come into contact with the sliding contact portion when said cylindrical insertion-side connector body of said second connector portion is inserted into said insertion hole portion of said first connector portion; and a prevention member including a sliding contact portion configured to come into sliding contact with the outer peripheral surface of said cylindrical insertion-side connector body of the second connector portion and to thereby be bent and brought into close contact with the outer peripheral surface of the cylindrical insertion-side connector body to shut off the distal end portion of the outer peripheral surface of said cylindrical insertion-side connector body from a distal end side so that the prevention member can prevent moisture from flowing from the distal end side toward the plurality of electrical contact portions, wherein each of the removing member and the prevention member is an annular member including a fixing portion which is fixed on the inner peripheral surface of the insertion hole portion of the first connector portion. a first connector portion including an insertion hole portion and a ring-shaped terminal juxtaposition portion on which a plurality of terminals are juxtaposed along an inner peripheral surface of the insertion hole portion; a second connector portion including a cylindrical insertion-side connector body having an outer peripheral surface and a ring-shaped terminal juxtaposition portion on which a plurality of electrical contact portions are juxtaposed in a circumferential direction on said outer peripheral surface of the cylindrical insertion-side connector body, wherein said plurality of electrical contact portions of said second connector portion are configured to be connected to the plurality of terminals of the first connector portion when said cylindrical insertion-side connector body of said second connector portion is inserted into said insertion hole portion of said first connector portion; a cylindrical insertion-side connector body having an outer peripheral surface and a ring-shaped terminal juxtaposition portion on which a plurality of electrical contact portions are juxtaposed in a circumferential direction on said outer peripheral surface of the cylindrical insertion-side connector body, a removing member provided in the first connector portion and including a sliding contact portion which is configured to remove moisture on the plurality of electrical contact portions by coming into sliding contact with the outer peripheral surface of said cylindrical insertion-side connector body when the plurality of terminals of said first connector portion are connected to the plurality of electrical contact portions of said second connector portion, a distal end portion of the outer peripheral surface of said cylindrical insertion-side connector body being configured to first come into contact with the sliding contact portion when said cylindrical insertion-side connector body of said second connector portion is inserted into said insertion hole portion of said first connector portion; and a prevention member including a sliding contact portion configured to come into sliding contact with the outer peripheral surface of said cylindrical insertion-side connector body of the second connector portion and to thereby be bent and brought into close contact with the outer peripheral surface of the cylindrical insertion-side connector body to shut off the distal end portion of the outer peripheral surface of said cylindrical insertion-side connector body from a distal end side so that the prevention member can prevent moisture from flowing from the distal end side toward the plurality of electrical contact portions, wherein