An endoscopic treatment device is used with an endoscope. This treatment device includes a transmission member with a flexible structure having a distal end portion to be inserted into a body and can be operated outside the body, a push rod coupled to the distal end portion, and first and second connecting members rotatably coupled to the push rod. The treatment device further includes first and second arm members rotatably coupled to the distal end portion of the connecting member, a holding member rotatably holding the respective arm at a predetermined interval therebetween, and first and second actuating members integrally formed with the arm members and can open/close when the transmission member actuates the first and second connecting members and the first and second arm members through the push rod. This device also includes a needle mounted on at least one of the first and second actuating members.