A surgical treatment device has an insertion section (302); an operation section (303) provided on one end of the insertion section; a treatment section (304) provided so as to extend from the other end of the insertion section; two holding members (308) provided on the treatment section and having individual holding surfaces; an opening/closing operation member (305) provided on the operation section and performing opening and closing operation of the holding members by moving at least either of the holding members; an angle change operation member (306) provided on the operation section and changing the angle of the treatment section to a predetermined value; a to-be-braked member disposed in the operation section and moved in association with the operation of the angle change operation section; and a braking means provided in the operation section and braking the to-be-braked member in association with the movement of the opening/closing operation member. The treatment section maintains a predetermined angle when the to-be-braked member is being braked by the braking means.