A slider (20, 50) for a slide fastener, comprising: a slider body (21, 51) which includes an upper wing plate (22, 52) having a pawl hole (43, 52c), a lower wing plate (30, 60) and a guide post (23, 53) for connecting the upper and lower wing plates (22, 52 and 30, 60); and a stopper mechanism (40, 70) for preventing the movement of the slider body (21, 51), wherein the slider body (21, 51) includes: front openings (26, 56) which are open on the left and right sides of the guide post (23, 53) between the upper and lower wing plates (22, 52 and 30, 60); a back opening (27, 57) which is open on the side opposite to the guide post (23, 53) in the front-back direction; and a Y-shaped element guide groove (28, 58) which is formed between the front openings (26, 56) and the back opening (27, 57), wherein the stopper mechanism (40, 70) includes a locking pawl (42, 72) that can protrude to the element guide groove (28, 58) through the pawl hole (43, 52c) of the upper wing plate (22, 52), wherein the lower wing plate (30, 60) has a raised portion (32, 32a, 62) on its inner surface (31,61), the raised portion (32, 32a, 62) extending in the front-back direction from the guide post (23, 53) toward the back opening (27, 57), wherein the raised portion (32, 32a, 62) includes: a first upper surface (33, 33a, 63) on the side of the guide post (23, 53), the first upper surface (33, 33a, 63) being horizontal and the highest in the raised portion (32, 32a, 62); and a second upper surface (34, 34a, 64) on the side of the back opening (27, 57), which is lower than the first upper surface (33, 33a, 63), and wherein the locking pawl (42, 72) can face the first upper surface (33, 33a, 63) in a state where the locking pawl (42, 72) protrudes to the element guide groove (28, 58), wherein the first upper surface (33, 33a, 63) includes: a uniform width portion in which its left and right sides are parallel to each other; and a wide portion in which the interval between its left and right sides (33e, 33e) is gradually enlarged from the end of the uniform width portion on the guide post (23, 53) side toward the guide post (23, 53), wherein the second upper surface (34, 64) is horizontal, and the first upper surface (33, 63) and the second upper surface (34, 64) are connected by an inclined surface (35, 65), wherein the uniform width portion is adjacent to the inclined surface (35, 65). a slider body (21, 51) which includes an upper wing plate (22, 52) having a pawl hole (43, 52c), a lower wing plate (30, 60) and a guide post (23, 53) for connecting the upper and lower wing plates (22, 52 and 30, 60); and a stopper mechanism (40, 70) for preventing the movement of the slider body (21, 51), wherein the slider body (21, 51) includes: front openings (26, 56) which are open on the left and right sides of the guide post (23, 53) between the upper and lower wing plates (22, 52 and 30, 60); a back opening (27, 57) which is open on the side opposite to the guide post (23, 53) in the front-back direction; and a Y-shaped element guide groove (28, 58) which is formed between the front openings (26, 56) and the back opening (27, 57), wherein the stopper mechanism (40, 70) includes a locking pawl (42, 72) that can protrude to the element guide groove (28, 58) through the pawl hole (43, 52c) of the upper wing plate (22, 52), wherein the lower wing plate (30, 60) has a raised portion (32, 32a, 62) on its inner surface (31,61), the raised portion (32, 32a, 62) extending in the front-back direction from the guide post (23, 53) toward the back opening (27, 57), wherein the raised portion (32, 32a, 62) includes: a first upper surface (33, 33a, 63) on the side of the guide post (23, 53), the first upper surface (33, 33a, 63) being horizontal and the highest in the raised portion (32, 32a, 62); and a second upper surface (34, 34a, 64) on the side of the back opening (27, 57), which is lower than the first upper surface (33, 33a, 63), and wherein the locking pawl (42, 72) can face the first upper surface (33, 33a, 63) in a state where the locking pawl (42, 72) protrudes to the element guide groove (28, 58), wherein the first upper surface (33, 33a, 63) includes: a uniform width portion in which its left and right sides are parallel to each other; and a wide portion in which the interval between its left and right sides (33e, 33e) is gradually enlarged from the end of the uniform width portion on the guide post (23, 53) side toward the guide post (23, 53), wherein the second upper surface (34, 64) is horizontal, and the first upper surface (33, 63) and the second upper surface (34, 64) are connected by an inclined surface (35, 65), wherein the uniform width portion is adjacent to the inclined surface (35, 65).