A cystourethroscope for prostate biopsy of the invention includes: an insertion portion that is insertable into a subject and that is bent at a predetermined curvature in a state under no external force； a grasping portion that includes a center axis in a straight line shape and that is connected to intersect with the insertion portion such that the center axis is positioned in a distal end cross section of the insertion portion； a distal end portion stretching in a convex direction of the bending from the distal end cross section； an observation portion formed on the distal end portion； and a treatment instrument insertion channel that is formed inside the insertion portion and that opens such that an inserted treatment instrument protrudes in an observation range of the observation portion.
