The present invention provides a seatbelt through-anchor and device capable of preventing jamming during an emergency. A through-anchor is rotatably attached to a vehicle interior wall and is folded back after a webbing extracted from a retractor is inserted through the through-anchor. The through-anchor includes: an insertion hole including an approximately linear lower edge on which the webbing slides, and a lateral edge curving from an end part of the lower edge; a lower-side part provided below the lower edge; and a bump part extending from an end of the lower-side part, protruding beyond a surface of the lower-side part in a direction corresponding to a vehicle interior side. The bump part includes peak parts protruding the furthest in the course of separating from the lateral edge, and includes, between each of the peak parts and the lateral edge, a first sliding surface including a curved surface outwardly protruding from the through-anchor.