An endoscope has an inserting tube to be inserted into a human body, first and second optical systems integrally secured to a tip end portion of the inserting tube. The first and second optical systems are for observing the in vivo tissues at different magnifications. A front end portion of the second optical system is protruded by a predetermined amount with respect to a front end portion of the first optical system so that the front end portion of said second optical system is located within a field of view of said second optical system.