A lubricant sealing structure which prevents lubricant from leaking out, from an interior of a device provided with a first member and a second member that rotate relative to one another about a central axis, through a gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f) between the first and second members, the lubricant sealing structure comprising: a labyrinth seal (20; 30; 40) for sealing the gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f), the labyrinth seal (20; 30; 40) being formed between a first surface portion on a first-member side and a second surface portion on a second-member side, the first and second surface portions facing each other; oil-repellent surfaces provided with oil repellency with respect to the lubricant, the oil-repellent surfaces being formed on each of the first and second surface portions; and an upstream-side oil-repellent surface provided with oil repellency, the upstream-side oil-repellent surface being formed on at least one of a first upstream-side surface portion and a second upstream-side surface portion, the first upstream-side surface portion being connected to the first surface portion and located on an upstream side in a leaking direction in which the lubricant leaks, and the second upstream-side surface portion being connected to the second surface portion and located on an upstream side in the leaking direction, wherein each of the oil-repellent surfaces and the upstream-side oil-repellent surface is provided with surface texturing in which fine grooves are formed in a prescribed groove array pattern; the fine grooves are provided with a groove width and a groove depth ranging from several microns to several tens of nanometers; and the groove array pattern is such that the fine grooves are arrayed at spacings ranging from several microns to several tens of nanometers characterized in that the labyrinth seal (20; 30; 40) is provided with a first gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f) having a first gap dimension; and, the first gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f) is formed with an oil reservoir having a second gap dimension that is larger than the first gap dimension, the oil reservoir being positioned at an intermediate section of the first gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f) in the leaking direction. a labyrinth seal (20; 30; 40) for sealing the gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f), the labyrinth seal (20; 30; 40) being formed between a first surface portion on a first-member side and a second surface portion on a second-member side, the first and second surface portions facing each other; oil-repellent surfaces provided with oil repellency with respect to the lubricant, the oil-repellent surfaces being formed on each of the first and second surface portions; and an upstream-side oil-repellent surface provided with oil repellency, the upstream-side oil-repellent surface being formed on at least one of a first upstream-side surface portion and a second upstream-side surface portion, the first upstream-side surface portion being connected to the first surface portion and located on an upstream side in a leaking direction in which the lubricant leaks, and the second upstream-side surface portion being connected to the second surface portion and located on an upstream side in the leaking direction, wherein each of the oil-repellent surfaces and the upstream-side oil-repellent surface is provided with surface texturing in which fine grooves are formed in a prescribed groove array pattern; the fine grooves are provided with a groove width and a groove depth ranging from several microns to several tens of nanometers; and the groove array pattern is such that the fine grooves are arrayed at spacings ranging from several microns to several tens of nanometers characterized in that the labyrinth seal (20; 30; 40) is provided with a first gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f) having a first gap dimension; and, the first gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f) is formed with an oil reservoir having a second gap dimension that is larger than the first gap dimension, the oil reservoir being positioned at an intermediate section of the first gap portion (21a-21e, 31a-31e, 41a-41e, 141a-141f) in the leaking direction.