An endoscopic surgery tool in which an image pickup device is provided on a hollow guide component that penetrates a body wall of a living body and guides a surgical tool into a body cavity, includes: a detection device that detects an amount of change in the tilt of the guide component when the guide component is tilted relative to the body wall using the portion passing through the body wall as a support point and a correction device that calculates from the tilt change amount an amount of movement of the image pickup device that moves in conjunction with the tilting of the guide component, and makes corrections in order that an observation image from the image pickup device before the guide component was tilted is maintained after it has been tilted.