An endoscope with an objective lens, wherein the objective lens has an angle of view (2ω) of 100° or greater at a wide-angle end, and comprising, in order from an object side thereof, a positive first group, a negative second group and a positive third lens group, wherein: said third group comprises a positive first subgroup and a positive second subgroup, a lens subgroup in at least said second group is configured to move to bring about a change in a focal length of a whole system and to correct an image position in accordance with the change in the focal length, and one subgroup in said second group and said third group is configured to move to an image side from a longer working distance side toward a shorter working distance side to correct a focal position in accordance with the change in the working distance, and characterized in that said objective lens satisfies the following conditions while moving to the image side from the longer working distance side: 0.4 < D 12 t − D 12 w / fw ≤ 1.077 0.02 < ΔDwd / fw < 0.4 0 < rb + ra / rb − ra < 2 − 0.7 < 1 / βwd < 0.2 where fw is a focal length of a whole system at the wide-angle end, a figure being obtained in a far end-defining working distance; D12w is a spacing between the first group and the second group at the wide-angle end; D12t is a spacing between the first group and the second group at a telephoto end; ΔDwd is the travelled distance of a moving group upon changing of the working distance from a far end to a near end, provided that a plus sign is indicative of a direction of movement of the moving group to an image side; ra is a radius of curvature of an image-side surface of a first lens in the first group; rb is a radius of curvature of an object-side surface of a second lens in the first group; and βwd is an imaging magnification of the moving group upon changing of the working distance from a far end to a near end, a figure being obtained at the wide-angle end in a far end-defining working distance. said third group comprises a positive first subgroup and a positive second subgroup, a lens subgroup in at least said second group is configured to move to bring about a change in a focal length of a whole system and to correct an image position in accordance with the change in the focal length, and one subgroup in said second group and said third group is configured to move to an image side from a longer working distance side toward a shorter working distance side to correct a focal position in accordance with the change in the working distance, and where fw is a focal length of a whole system at the wide-angle end, a figure being obtained in a far end-defining working distance; D12w is a spacing between the first group and the second group at the wide-angle end; D12t is a spacing between the first group and the second group at a telephoto end; ΔDwd is the travelled distance of a moving group upon changing of the working distance from a far end to a near end, provided that a plus sign is indicative of a direction of movement of the moving group to an image side; ra is a radius of curvature of an image-side surface of a first lens in the first group; rb is a radius of curvature of an object-side surface of a second lens in the first group; and βwd is an imaging magnification of the moving group upon changing of the working distance from a far end to a near end, a figure being obtained at the wide-angle end in a far end-defining working distance.