An objective of the present invention is to adequately enlarge a field of view, and distribute sufficient illumination light within the enlarged field of view. Provided is a capsule endoscope wherein: an object lens unit (11) has a lens which is a negative-power meniscus lens which is positioned nearest the object side with a convex surface turned toward the object side such that the convex surface faces outward； an illumination unit (13) comprises a light source and an illumination window member (19)； the light source is positioned so as to enclose the periphery of the lens； the illumination window member is formed in a substantially annular shape enclosing the periphery of the lens and is located nearer to the imaging side than the outermost diameter portion of the convex surface of the lens wherethrough a light beam passes； a blocking member which blocks the entry of the illumination light upon the object lens unit is positioned between the illumination window member and the lens； and the capsule endoscope satisfies the conditional formulae (1), (2) -10<；f1/f<；-4 (1), 0.7<；d1/f<；2 (2), where f1 is the focal length of the lens, f is the focal length of the object lens unit, and d1 is the distance between the lens and another lens which is positioned adjacent to the image side of the lens.La présente invention vise à agrandir de façon appropriée un champ de vision, et distribuer une lumière d'éclairage suffisante dans le champ de vision agrandi. L'invention concerne un endoscope à capsule, dans lequel : une unité de lentille d'objet (11) a une lentille qui est un ménisque à puissance négative, qui est la plus proche du côté objet, ayant une surface convexe tournée vers le côté objet, de telle sorte que la surface convexe fait face vers l'extérieur ； une unité d'éclairage (13) comprend une source de lumière et un élément de fenêtre d'éclairage (19) ； la source de lumière est positionnée de façon à entourer la périphérie de la lentille ； l'élément de fenêtre
