A telescope includes a monocular assembly, an optical lens assembly, and a focus cover. The monocular assembly includes a monocular and a light-shielding tube movably sleeved at the monocular. The optical lens assembly is disposed in the light-shielding tube and is fixed on the monocular. The focus cover is detachably disposed on an end portion of the light-shielding tube and includes a tubular carrier, a focus sheet, and a covering body. The tubular carrier has a carrying portion formed on an inner side thereof, and includes a connecting portion and an accommodating portion respectively arranged at two opposite sides of the carrying portion. The connecting portion is detachably fastened to the end portion. The focus sheet is detachably positioned at the carrying portion and is arranged in the accommodating portion. The covering body is detachably fastened to the accommodating portion for shielding the focus sheet.