A sacroiliac belt (9, 14, 16) comprising a belt pair adapted to form a pelvic holding loop (13a, 13b) to hold a user's pelvis (γ) from a buttock side or a lumbar back side, entirely wrapping the pelvis (γ), the belt pair comprising: a ring-shaped ilium belt (1, 1 a) adapted to be wound around the user's waist, surrounding the user's right and left ilia; and a second belt (5, 5a, 5b, 5c) selected from: either a buttock belt adapted to be wound around the user's waist passing under the user's buttocks, lifting up the buttocks; or a lumbar belt adapted to be wound around the user's waist passing the user's lumbar back, which is a back side of the user's lumbar curve located immediately above the pelvis (γ), the second belt (5, 5a, 5b, 5c) being shorter than the ilium belt (1, 1a), and both ends of the second belt (5, 5a, 5b, 5c) being adapted to be connected to the ilium belt (1, 1 a) through a reversible connection, characterized in that the sacroiliac belt (9, 14, 16) comprises rings at both ends of the second belt (5, 5a, 5b, 5c), the illium belt (1,1a) being adapted to be placed through the rings, wherein, while the ilium belt (1, 1a) is placed through the rings, the both ends of the second belt (5, 5a, 5b, 5c) are connected to the ilium belt (1, 1a) in a pair of connection areas placed inside both ends of the ilium belt (1, 1a) through a said reversible connection, so that the both ends of the second belt (5, 5a, 5b, 5c) are reversibly connected to the pair of connection areas on the ilium belt (1, 1a) via hook and loop fasteners that consist of first and second components (4, 6), the first components attached in the connection areas on the ilium belt (1, 1a) and the second components attached on the both ends of the second belt (5, 5a, 5b, 5c). a ring-shaped ilium belt (1, 1 a) adapted to be wound around the user's waist, surrounding the user's right and left ilia; and a second belt (5, 5a, 5b, 5c) selected from: either a buttock belt adapted to be wound around the user's waist passing under the user's buttocks, lifting up the buttocks; or a lumbar belt adapted to be wound around the user's waist passing the user's lumbar back, which is a back side of the user's lumbar curve located immediately above the pelvis (γ), the second belt (5, 5a, 5b, 5c) being shorter than the ilium belt (1, 1a), and both ends of the second belt (5, 5a, 5b, 5c) being adapted to be connected to the ilium belt (1, 1 a) through a reversible connection, characterized in that the sacroiliac belt (9, 14, 16) comprises rings at both ends of the second belt (5, 5a, 5b, 5c), the illium belt (1,1a) being adapted to be placed through the rings, wherein, while the ilium belt (1, 1a) is placed through the rings, the both ends of the second belt (5, 5a, 5b, 5c) are connected to the ilium belt (1, 1a) in a pair of connection areas placed inside both ends of the ilium belt (1, 1a) through a said reversible connection, so that the both ends of the second belt (5, 5a, 5b, 5c) are reversibly connected to the pair of connection areas on the ilium belt (1, 1a) via hook and loop fasteners that consist of first and second components (4, 6), the first components attached in the connection areas on the ilium belt (1, 1a) and the second components attached on the both ends of the second belt (5, 5a, 5b, 5c). either a buttock belt adapted to be wound around the user's waist passing under the user's buttocks, lifting up the buttocks; or a lumbar belt adapted to be wound around the user's waist passing the user's lumbar back, which is a back side of the user's lumbar curve located immediately above the pelvis (γ), the second belt (5, 5a, 5b, 5c) being shorter than the ilium belt (1, 1a), and both ends of the second belt (5, 5a, 5b, 5c) being adapted to be connected to the ilium belt (1, 1 a) through a reversible connection, characterized in that the sacroiliac belt (9, 14, 16) comprises rings at both ends of the second belt (5, 5a, 5b, 5c), the illium belt (1,1a) being adapted to be placed through the rings, wherein, while the ilium belt (1, 1a) is placed through the rings, the both ends of the second belt (5, 5a, 5b, 5c) are connected to the ilium belt (1, 1a) in a pair of connection areas placed inside both ends of the ilium belt (1, 1a) through a said reversible connection, so that the both ends of the second belt (5, 5a, 5b, 5c) are reversibly connected to the pair of connection areas on the ilium belt (1, 1a) via hook and loop fasteners that consist of first and second components (4, 6), the first components attached in the connection areas on the ilium belt (1, 1a) and the second components attached on the both ends of the second belt (5, 5a, 5b, 5c).