The present invention makes an objective lens easier to handle during disinfection or sterilization and protects the objective lens during, for example, transport, storage, or handling. The present invention provides an objective-lens protector including a substantially ring-shaped mounting portion surrounding a circumference of an objective lens, the mounting portion detachably mounted on the objective lens such that a threaded mount formed on the objective lens for mounting the objective lens to a microscope main body is exposed; a protecting member fixed to the mounting portion, extending substantially along the entire length of the objective lens mounted on the mounting portion, and arranged at a distance outwardly in a radial direction of the objective lens so as to surround the objective lens; and a locking mechanism provided on the mounting portion to prevent the objective lens from moving relative to the mounting portion in a circumferential direction.