A surgical treatment instrument according to the invention includes an insertion portion, an operation portion provided on one end of the insertion portion, a treatment portion provided so as to extend from the other end of the insertion portion, two gripping members provided on the treatment portion, each having a gripping face, an open/close operating member provided on the operation portion to perform opening/closing by at least one of the two griping members being moved, variable angle operating members respectively provided on the operation portion to change the treatment portion to a predetermined angle, a braked member provided within the operation portion and operating in conjunction with the operation of the variable angle operation portion, and a braking member provided within the operation portion to brake the braked member by operating in conjunction with the operation of the open/close operation member, wherein the treatment portion maintains a predetermined angle by the braked member being braked by the braking member.