An evaluating device of a flexural property includes a holder, a body disposed on the holder and capable of being moved along with a length of direction of the holder, a clamp coupled to the body to be rotated on the body and fixing a first side of the specimen to be evaluated, and a pressing part disposed over the clamp and pressing a second side of the specimen opposite to the first side and disposed upper than the first side of the specimen to bend the specimen, and an evaluation method of a flexural property of the bent specimen using the same.