A conical roller bearing comprising: an outer ring having ring shape; an inner ring, having ring shape, and disposed on an inner circumferential side of the outer ring; a cage, disposed between the outer ring and the inner ring, and including a plurality of pockets arranged circumferentially at equal intervals; and a plurality of conical rollers, disposed individually in the pockets, wherein the outer ring includes on an inner circumference thereof an outer-ring-side raceway surface on which the conical rollers roll, the inner ring includes an inner-ring-side raceway surface on which the conical rollers roll on an outer circumference thereof, a small-diameter-side end portion which is provided at a small-diameter side across the inner-ring-side raceway surface, and a large-diameter-side end portion which is provided at a large-diameter side across the inner-ring-side raceway surface, the cage includes a first annular portion which has a ring shape and is provided in a position corresponding to the small-diameter-side end portion on one side of the pockets in an axial direction of the inner ring, a second annular portion which has a ring shape and is provided in a position corresponding to the large-diameter-side end portion on the other side of the pockets in the axial direction, and pillar portions which are provided individually on both circumferential sides of the pockets, the conical rollers are individually brought into engagement with the pockets in a position lying further radially outwards than a rotational center of the conical rollers, the inner ring includes an annular groove between the inner-ring-side raceway surface and the small-diameter-side end portion, characterized in that the cage includes an erected portion which extends from the first annular portion towards the annular groove, the erected portion includes a first inclined portion which is inclined towards the conical rollers while extending from the first annular portion towards the annular groove, and a second inclined portion which is inclined towards the small-diameter-side end portion while extending from the first inclined portion towards the annular groove, so that, when the erected portion is deformed during assembly, the erected portion is bent toward the large-diameter-side end portion at a root of the first inclined portion and is bent toward the small-diameter-side end portion at a root of the second inclined portion, and the second inclined portion is configured to be brought into engagement with the annular groove in the axial direction of the inner ring. an outer ring having ring shape; an inner ring, having ring shape, and disposed on an inner circumferential side of the outer ring; a cage, disposed between the outer ring and the inner ring, and including a plurality of pockets arranged circumferentially at equal intervals; and a plurality of conical rollers, disposed individually in the pockets, wherein the outer ring includes on an inner circumference thereof an outer-ring-side raceway surface on which the conical rollers roll, the inner ring includes an inner-ring-side raceway surface on which the conical rollers roll on an outer circumference thereof, a small-diameter-side end portion which is provided at a small-diameter side across the inner-ring-side raceway surface, and a large-diameter-side end portion which is provided at a large-diameter side across the inner-ring-side raceway surface, the cage includes a first annular portion which has a ring shape and is provided in a position corresponding to the small-diameter-side end portion on one side of the pockets in an axial direction of the inner ring, a second annular portion which has a ring shape and is provided in a position corresponding to the large-diameter-side end portion on the other side of the pockets in the axial direction, and pillar portions which are provided individually on both circumferential sides of the pockets, the conical rollers are individually brought into engagement with the pockets in a position lying further radially outwards than a rotational center of the conical rollers, the inner ring includes an annular groove between the inner-ring-side raceway surface and the small-diameter-side end portion, characterized in that the cage includes an erected portion which extends from the first annular portion towards the annular groove, the erected portion includes a first inclined portion which is inclined towards the conical rollers while extending from the first annular portion towards the annular groove, and a second inclined portion which is inclined towards the small-diameter-side end portion while extending from the first inclined portion towards the annular groove, so that, when the erected portion is deformed during assembly, the erected portion is bent toward the large-diameter-side end portion at a root of the first inclined portion and is bent toward the small-diameter-side end portion at a root of the second inclined portion, and the second inclined portion is configured to be brought into engagement with the annular groove in the axial direction of the inner ring.