Abstract: The specification discloses an improved internal surgical stapler in which staples are pushed by a comb-like ram out of a magazine of a frame and are clinched by an anvil hinged to the frame and releasably latched to the frame by a latch. The latch includes a latch rod having a thumb grip and also provided with a leaf spring catch. The rod normally is in a retracted position in which its forward end is in the magazine. Then, when the user grips the thumb grip and the anvil and squeezes, the anvil is swung toward the magazine to clamp layers to be stapled and the rod is pushed out of the magazine and into a leaf spring latch in the anvil and latches. The rod is splined to the magazine until the end of this latching movement. To release the latch, the thumb grip is turned to turn the rod to move barbs on the rod out of latching holes in arms of the leaf spring catch.